"Please turn with me in your Bibles to the sixth chapter of Paul’s Second Letter to the Corinthians. 2 Corinthians chapter 6. One of the most devastating attacks on the life and health of the church throughout all of church history has been what is known as the ecumenical movement—the downplaying of doctrine in order to foster partnership in ministry between (a) genuine Christians and (b) people who were willing to call themselves Christians but who rejected fundamental Christian doctrines.

In the latter half of the 19th century, theological liberalism fundamentally redefined what it meant to be a Christian. Being a Christian had nothing to do, the liberals said, with believing in doctrine. It didn’t matter if you believed in an inerrant Bible; the scholarship of the day had debunked that! It didn’t matter if you believed in the virgin birth and the deity of Christ; modern science disproved that! It didn’t matter if you embraced penal substitutionary atonement; “blood sacrifice and a wrathful God are just primitive and obscene, and anyway, man is not fundamentally sinful but basically good!” No, what mattered was one’s experience of Christ, and whether we live like Christ. “And we don’t need doctrine to do that! Doctrine divides!” Iain Murray wrote of that sentiment, “‘Christianity is life, not doctrine,’ was the great cry. The promise was that Christianity would advance wonderfully if it was no longer shackled by insistence on doctrines and orthodox beliefs” (“Divisive Unity,” 233).
The result of this kind of thinking was the social gospel of the early 20th century. If what it means to be a Christian has little to do with creeds and everything to do with deeds, then what makes someone a Christian is whether they’re laboring for the betterment of society—feeding the hungry, sheltering the homeless, working for justice, and so on. And so what you saw taking place was, across denominational lines, professing “Christians” were coming together to promote unity around a common mission—even if they didn’t share a common faith. In 1908, more than 30 denominations representing over 18 million American Protestants set their doctrinal differences aside and met in Philadelphia at what is called the Federal Council of Churches. And their great concern was not the Gospel, but how to address the social issues of the day: race relations, international justice, reducing armaments, education, and regulating the consumption of alcohol. This was the beginning of the modern ecumenical movement.
Now, in each of these denominations there were faithful Christians who recognized that—as much as social ills mattered—the body of Christ was not defined most fundamentally by a common social agenda, but by a common confession of faith in the Christ of Scripture. These faithful men, led by the great Presbyterian professor J. Gresham Machen, among others, understood that there were certain fundamental truths that no one claiming to be a Christian could deny. A Christ who is not fully God is a fundamentally different Christ than one who is fully God. A salvation that can be more-or-less earned through good morals and good deeds is a fundamentally different salvation than the one purchased freely on the cross by our wrath-bearing Substitute. A religion built upon the authority of man’s ideas is a fundamentally different religion than one built upon the authority of God as revealed in Scripture. And so these men—pejoratively labeled Fundamentalists—insisted that the doctrinal fundamentals of the Christian faith were non-negotiable, and that, if they were abandoned, it didn’t matter how many people-who-called-themselves-Christians you could gather into one place: there was no true unity.
The conflict between the Liberals and the so-called Fundamentalists raged on through the ensuing years. In 1948, the World Council of Churches convened in Amsterdam, and embraced as Christian anyone who merely said they believed that Jesus Christ was God and Savior. Delegates from 147 churches brought Protestants, Anglicans, and Eastern Orthodox persons together from all over the world. Once again, the goal was to show strength in numbers—to portray to the world that “Christianity” was visibly united, a cultural force—and to pool support for worldwide missions and social justice. In every case, these movements and councils lamented the division across doctrinal and denominational lines, and argued that if Christianity is to have any genuine influence in the world, we must be big. And so we must come together. A divided church is an offense to God and a cause of her ineffectiveness in the world, they said.
By the 1950s, the Billy Graham crusades had become an evangelistic phenomenon. Tens of thousands were flocking to hear this evangelist speak, and thousands were making professions of faith in Christ. Now this caught the attention of the liberal ecumenical guys, because Graham believed in all the fundamental doctrines that they rejected. He believed in the sinfulness of man! and the need of a spiritual Savior from sin! and he called for conversions! And yet he was drawing crowds! When Graham began his first crusade in Britain in 1954, the liberal Anglicans denounced him. But by the end of the crusade several months later, they were sitting on the platform alongside him! The Archbishop of Canterbury even gave the benediction at the final meeting!
And it was all—as it always is—numbers driven. One of the Anglican liberals said of partnering with Graham, “What does fundamentalist theology matter compared with gathering in the people we have all missed?” “Who cares about the theology? Just get the people in the seats!” And sadly enough, the uncrucified lust for influence worked in both directions. Iain Murray writes, “But the truth was that [Graham] wanted the cooperation of these men for the aid that their reputations gave to his work, and for the way it could secure wider denominational support. Winning the mainline denominations remained the primary objective and that could not be done without the good will of the leaders. So both sides were motivated by an ulterior motive. On Graham’s side the motive was to get a wider hearing for the gospel, but in order to do this, he adopted an attitude towards false teachers that is not compatible with the New Testament” (“Divisive Unity,” 240).
And though the motive is always pure—to influence the enemies of the Gospel to be swayed from their opinions and embrace the Gospel—it always works in the opposite direction. 1 Corinthians 15:33 says, “Do not be deceived: ‘Bad company corrupts good morals.’” “Oh, I’m just partnering with them so that I can minister to them and so that they can get saved!” Paul says, “No, don’t be deceived! Good morals do not reform bad company; bad company corrupts good morals.” And that is precisely what happened to Billy Graham. His biographer, William Martin, records Graham as saying, “The ecumenical movement has broadened my viewpoint.” “I don’t think the differences [between evangelicalism and Roman Catholicism] are important as far as personal salvation is concerned.” And “I feel I belong to all the churches. I am equally at home in an Anglican or Baptist or a Brethren assembly or a Roman Catholic church” (“Divisive Unity,” 243). And in 1997, in a now-famous interview with the arch-liberal Robert Schuller, Graham demonstrates the inevitable end of ecumenism when he says, “I think that everybody that loves or knows Christ, whether they are conscious of it or not, they are members of the body of Christ. . . . They may not know the name of Jesus but they know in their hearts that they need something they do not have, and they turn to the only light they have, and I think that they are saved and going to be with us in heaven” (ibid, 243).
The force of the ecumenical battles could be felt throughout the 1960s, especially as they related to the widening gulf between Anglicanism and British Evangelicalism. Martyn Lloyd-Jones continually exhorted British Evangelicals to disassociate from an Anglican Church that had compromised with liberalism and Roman Catholicism, and to form an evangelical union of churches in its stead. He wrote, “We have evidence before our eyes that our staying amongst [the non-evangelicals] does not seem to be converting them to our view but rather to a lowering of the spiritual temperature of those who are staying amongst them and an increasing tendency to doctrinal accommodation and compromise” (ibid., 242). And as I said, that is always what happens, because bad company corrupts good morals. In the mid-60s, the Roman Catholic Church convened the Second Vatican Council, and the effects of the ecumenical movement could be felt throughout. Vatican II was in large measure an attempt to soften and liberalize Catholic dogma. As the years progressed, Anglicanism grew more and more polluted with theological compromise both in the direction of liberalism and Roman Catholicism.
But that’s not the end of the story. In March of 1994, the ecumenical movement breathed new life, when 30 well-known evangelicals and influential Roman Catholics signed and published the document titled “Evangelicals and Catholics Together” (ECT). And in precisely the same spirit as the original social gospel compromisers, the authors and signatories of this document totally downplay and diminish the fundamental doctrinal differences that separate evangelicals and Roman Catholics, so that we can stand “united” to promote a “Christian” view of society and social issues. Now, Rome has not budged on their insistence that the Roman Catholic Magisterium, and not Scripture alone, is the infallible authority for the church. They have not rescinded the anathemas of the Council of Trent, which condemn to hell anyone who believes that a man is justified by faith alone, apart from works. And yet in the name of “the right ordering of society,” and the assertion that “politics, law, and culture must be secured by moral truth,” these cardinal doctrines of the Christian faith are marginalized, as if they were not absolutely fundamental to salvation. And evangelicals of no less stature than Os Guiness and J. I. Packer fixed their signatures to this document!
Religious freedom, abortion issues, parental choice in education, a free-market economy, pro-family legislation, and a responsible foreign policy—uniting on these issues are more important to these men than the Gospel that we are declared righteous by grace alone through faith alone in Christ alone, that Christ alone is the Head of the Church, the sole Mediator between God and men, and that the sacrifice He offered as our Great High Priest is so sufficient that it does not need to be repeated each week in wine and wafers!
15 years later, in late 2009, a sort of “ECT II” was published in what is called The Manhattan Declaration. Focusing on the perceived need for co-belligerence on social issues like religious freedom and the right to life, the declaration begins this way: “We, as Orthodox, Catholic, and Evangelical Christians, have gathered . . . to make the following declaration.” And so in the first sentence, the writers of the Manhattan Declaration deny that belief or unbelief in the very heart of the Gospel makes someone a Christian! You can be an “Orthodox Christian” while believing you’re saved by baptism; you can be a “Catholic Christian” while believing that Christ’s death is insufficient to secure your salvation. You don’t have to be Evangelical—that is, you don’t need the Gospel, the Evangel—to be a Christian! It goes on, “We act together in obedience to the one true God . . . .” And yet it is utterly absurd to suggest that it is possible to obey the one true God while rejecting the one true Gospel! Paul says that even if he himself, or even an angel from heaven—no matter if he calls himself a Christian—preaches a gospel contrary to the Gospel preached in Scripture, “he is to be accursed!” (Gal 1:8).
And so the story of the ecumenical movement is exactly the same—from the Federal Council of Churches in 1908, to the Manhattan Declaration in the present day—it is the exact same story: Redefine Christianity so that faith in the Christ of Scripture and/or the Gospel of Scripture is unnecessary, so that you can partner with enemies of the Gospel who call themselves Christians, form a large group and seize cultural influence. But Francis Schaeffer captured well the fundamental failure of the ecumenical movement when he wrote, “What is the use of evangelicalism seeming to get larger and larger if sufficient numbers under the name evangelical no longer hold to that which makes evangelicalism evangelical?” (Murray, 243). If you lose the Gospel, you have no true unity! because the mission of Christ’s Church in this world is not to exercise dominion over society and culture, it is to preach the Gospel to every creature! to proclaim the Gospel of repentance for the forgiveness of sins through faith alone in Christ alone! so that we relieve the eternal suffering that sinful men and women are condemned to face as the just penalty for their sins!
And any time, throughout all of church history, where the professing church has forgotten that, and—however well-intentioned— has compromised to partner in ministry with those who do not share a common faith in the one and only Gospel of Jesus Christ—she has ceased to be the church, and has courted the judgment rather than the blessing of God. The 19th-century Scottish minister Horatius Bonar didn’t have to live in the midst of 20th-century ecumenism to understand this. He wrote, “Fellowship between faith and unbelief must, sooner or later, be fatal to the former.” Iain Murray comments on this saying, “This is so, not because error is more powerful than truth, but because if we befriend the advocates of error, we will be deprived of the aid of the Spirit of truth. If we retain orthodoxy in word, we shall certainly lose its power. Wrong teaching about Christ and the gospel, according to Scripture, is deadly dangerous. Out of good motives we may seek to win influence for the gospel among those who are not its friends, but when we do so at the expense of truth, we shall not prosper in the sight of God” (ibid., 244).
There can be no partnership in ministry between the body of Christ who has been saved by the Gospel, and the enemies of that Gospel. No matter how many other good things they agree on—whether religious liberty, the unborn child’s right to life, the sanctity of marriage, the deity of Christ, the Trinitarian nature of God—if you do not have the Gospel, you do not have Jesus! And if you don’t have Jesus, you simply cannot be united to those who do.
Text Introduction & Context
And as we come to our passage this morning, 2 Corinthians 6:14 to chapter 7 verse 1, we find that that is precisely Paul’s message to the Corinthians. Follow along with me as I read, starting in 2 Corinthians 6:14: “Do not be bound together with unbelievers; for what partnership have righteousness and lawlessness, or what fellowship has light with darkness? 15Or what harmony has Christ with Belial, or what has a believer in common with an unbeliever? 16Or what agreement has the temple of God with idols? For we are the temple of the living God; just as God said, ‘I will dwell in them and walk among them; and I will be their God, and they shall be My people.’ 17Therefore, ‘Come out from their midst and be separate,’ says the Lord. ‘And do not touch what is unclean; And I will welcome you. 18And I will be a father to you, And you shall be sons and daughters to Me,’ Says the Lord Almighty. 7:1Therefore, having these promises, beloved, let us cleanse ourselves from all defilement of flesh and spirit, perfecting holiness in the fear of God.”
The apostolic instruction could not be clearer: because there is a radical difference between believers and unbelievers at the most fundamental level, there can be no partnership between them in ministry.
Now, you can hear the consistent emphasis in this passage on the theme of idolatry. Verse 16 asks, “What agreement has the temple of God with idols?” And the context of the Old Testament quotations to “Come out from their midst and be separate” and to “not touch what is unclean” has to do with Israel’s separation from the idolatry of the pagan nations. And Corinth is one of those pagan nations! When the Corinthian Christians came to Christ, they had to repudiate the Greco-Roman polytheistic system of idol worship. Like the Christians in the pagan city of Thessalonica, they had to “turn to God from idols to serve [the] living and true God” (1 Thess 1:9). And they did that! But their conversion to Christ didn’t remove them from a society where the worship of idols absolutely dominated everyday life. Holidays, festivals, celebrations, even down to the ideology and philosophy that dominated everyday conversation was influenced by pagan temple worship. Idolatry was simply part of their culture, and they had to do everything they could to guard against any syncretism—any blending of idolatrous worship with Christianity.
And the Apostle Paul knew that, and so he addressed the issue of idolatry with the Corinthians in his previous letter to them. He devotes almost two entire chapters in 1 Corinthians—chapters 8 and 10—to instructing them how to live in a society dominated by idolatry without compromising commitment to Christ. And in those chapters he makes clear the absolute incompatibility between the worship of Christ and the worship of idols. In 1 Corinthians 10:7 he says, simply, “Do not be idolaters.” In verse 14: “Therefore, my beloved, flee from idolatry.” Back in chapter 6 verse 9 he says that idolaters will not enter the kingdom of heaven.
And in chapter 10, verses 16 to 22, he explains why. Even though idols don’t exist and are no true gods at all, it’s not that there’s no spiritual component to idolatry. Verse 20: “No, but I say that the things which the Gentiles sacrifice, they sacrifice to demons and not to God.” “Paul, you just said that an idol is nothing, and sacrifices to idols are nothing. So we should be able to take part in those rituals, right? They aren’t true gods!” Paul says, “No. They’re not true gods because there’s no such thing. But they are demons.” Listen: every false religion in the world is not just wrong; it is demonic. It is energized and powered by the kingdom of darkness that is ruled by Satan himself. Paul says the gods of the pagans are demons. And just as when we sit down at the Lord’s table to worship Christ we share in the body and blood of Christ, so also when the idolaters sacrifice to their demonic gods they are partaking of fellowship with demons. And, verse 20, “I do not want you to become sharers in demons. You cannot drink the cup of the Lord and the cup of demons; you cannot partake of the table of the Lord and the table of demons!” “You can’t participate in the worship of Christ while you continue to participate in the worship of demons! That is just ridiculous! There is absolutely no fellowship or spiritual partnership between the people of God and the people of this world!”
Now, that was Paul’s concern throughout the letter of First Corinthians. But here in Second Corinthians there’s a bit of a different context. They’re still guarding themselves against the paganism of their surrounding culture, but the pressing issue as Paul writes Second Corinthians isn’t so much the pressure of unbelieving paganism, but rather the corrupting doctrine of the Judaizing false apostles—these professing Christians who are claiming that faith in Christ is necessary, but not enough for salvation; you also have to be circumcised, and observe the Mosaic ceremonies as well! And in order to make room for their false doctrine, these interlopers have done everything they could to undermine Paul’s integrity and credibility with the Corinthians—hurling accusation after accusation against him.
And from our study of 2 Corinthians, we’ve learned that, through Paul’s severe letter, the majority the church saw these charlatans for what they were and reaffirmed their loyalty to Paul. But there was still a significant minority who were deceived. And so before visiting them again, Paul writes this letter to affirm his love for the repentant majority, and to exhort the unrepentant minority to break fellowship with these false teachers and return to him and the unadulterated Gospel he preaches with their whole hearts.
And last time, we looked at the two passages which surround this morning’s passage: chapter 6 verses 11 to 13, and chapter 7 verses 2 to 4. Chapter 6 verse 14 to chapter 7 verse 1 comes sandwiched in between a twofold appeal for them to open their hearts and be reconciled to him and affirm their loyalty to the Gospel he preaches. But because the heart of this relational crisis is a moral crisis, in between that twofold appeal for reconciliation, he calls them to separate from these false apostles.
You say, “Wait a minute. You said these false apostles were Judaizers—that they were professing Christians who were just saying that you needed to add a few religious ceremonial works to your faith in Christ for salvation. But this text is all about separating oneself from pagan idolatry. How does that work?” And that’s the genius of this passage. Paul is saying, “Do you remember my instruction from my previous letter concerning the necessity of your total break from the idolatry and the paganism of your culture? Do you remember how I explained how incongruous it is to be involved in a spiritual partnership with Christ and with demons? Well, my dear Corinthians, that’s not only true of the out-and-out heathen—to the pagan idolaters who deny Christ outright. It also applies even to professing Christian teachers who corrupt the Gospel of salvation by grace alone through faith alone in Christ alone! Because these false apostles teach you that salvation comes by faith in Christ plus religious ritualism, they preach another gospel which is really no gospel at all! And though they call Christ their God, He is”—as Paul will say in chapter 11 verse 4—“another Jesus whom we have not preached, and therefore is nothing but a demon, right alongside the false gods of the Greco-Roman pantheon! They are idolaters! And just as much as you cannot have any spiritual partnership with the idols of the Gentiles, neither can you have any spiritual partnership with these heretics, who fashion a god into their own image and idolize a demon they call ‘Jesus!’ You must come out from them and be separate!”
What does this tell us, dear friends? What implications does this have for the philosophy and theology that undergirds the ecumenical movement? (1) It teaches us that simply calling yourself a Christian, and mentally assenting to the doctrine of the Trinity, and confessing faith in someone named “Jesus,” doesn’t automatically make you a Christian. (2) It teaches us that there are people who profess to be Christians but who are not Christians, because they’re not united to Him through faith in the Gospel. (3) It teaches us that there are people who will claim to “believe in Jesus,” who are nevertheless, as Paul calls them in this passage, unbelievers. (4) And it teaches us, therefore, that if we compromise by making light of the doctrinal differences that do genuinely divide us and unite together in ministry—even in the name of combatting genuine social evils like religious persecution, abortion, or racism—we are guilty of the grossest kind of idolatry, and are no better than pagans!
Now, all of that was introduction. And we’re going to spend at least two weeks on this text, because it is so rich and so applicable for all of us who are genuinely involved in Christian ministry. And the paragraph in 6:14 to 7:1 breaks down basically into three units. First, there is the call for separation that Paul lays down in verse 14—“Do not be unequally yoked with unbelievers”—along with five rhetorical questions that illustrate the incongruity and incompatibility between Christians and non-Christians. Second, the figure used in that final illustration in verse 16—that believers are the temple of God—is asserted and supported by several citations from the Old Testament, which call for separation and promise blessing for purity. And third, there is a summary exhortation in chapter 7 verse 1 that calls God’s people to purity and holiness on the basis of God’s gracious promises.
With the time we have left this morning, I’m going to aim to get through just that first point—the call for separation between believers and unbelievers, along with the five illustrations that give the reasoning for that call.
The Call for Separation (v. 14a)
So first, let’s consider the call for separation, by giving heed to Paul’s prohibition in chapter 6 verse 14. Paul writes, “Do not be bound together with unbelievers.” Or perhaps better translated by the ESV: “Do not be unequally yoked with unbelievers.”
Now, this term “to be unequally yoked with,” is a translation of the compound word heterozugeo, which is made up of the term heteros—which means “different”—and the word zugos, which is the word for “yoke.” And a yoke is a wooden crosspiece that you fasten over the necks of two animals, which is then attached to a plow or a cart that they’d pull. So it’s very much an agricultural image. There’s a double yoke, which sits on the necks of two animals as they plow side by side in the same direction. And the idea is: “Don’t get into a yoke with an animal that requires a different kind of yoke than you do.” Or perhaps, “Don’t yoke together two different animals who are going to be pulling in two different directions.”
And the imagery that Paul draws from comes from the Old Testament. The only other time this word heterozugeo is used, it’s used as an adjective in the Greek translation of Leviticus 19:19, where God commands Israel: “You shall not breed together two kinds of your cattle; you shall not sow your field with two kinds of seed, nor wear a garment upon you of two kinds of material mixed together.” When set alongside the prohibitions to not mix seeds or mix fabrics, this command is seen clearly to prohibit the cross-breeding of animals of different kinds. If you translate the Septuagint literally into English, it says, “You shall not breed your cattle with an animal that uses another yoke.” The same concept is repeated in Deuteronomy 22:10, which states, “You shall not plow with an ox and a donkey together.” In other words, don’t put an ox and a donkey in the same yoke and expect them to pull that plow in a harmonious, cooperative way. They have different levels of strength, they have a different manner of walking (a different gait), and they have very different constitutions—the donkey, of course, being much more stubborn than the ox! These two different kinds of animals are a mismatched pair, and it would be impossible for them to plow together in an effective manner.
By using this imagery, Paul is saying the same thing about partnership between believers and unbelievers. Just as yoking together two fundamentally different kinds of animals will result in incongruity and discord, so also are believers and unbelievers two fundamentally different “breeds”—fundamentally different kinds of people. And any intimate association or spiritual partnership between them will eventually only result in dissonance and difficulty. Believers and unbelievers are moving in different directions; we live in two different worlds; we’re energized by different powers, and motivated by different passions. To partner them together and expect them to plow in the same direction is ludicrous, and will only end in spiritual disaster.
Now, it’s important to state clearly what this call to separation from unbelievers does not mean. It does not mean isolationism. It does not mean that we cut off all contact between ourselves and the world, and retreat into monasticism and live as hermits in caves. It doesn’t mean that we withdraw from society into our little Christian bubble, where we live in a housing development or an apartment complex populated only by Christians, in a house that we bought from a Christian real estate agent, and drive a car that we bought from a Christian car dealer, that’s insured by a Christian insurance agent, that we drive our kids in to and from their Christian school, and only shop at a Christian grocery store, and on and on it goes. Not being unequally yoked with unbelievers doesn’t mean retreating into a Christian commune where you’re cut off from the world! It can’t mean that.
You say, “How do you know?” Well, the same Paul who wrote 2 Corinthians 6:14 also wrote 1 Corinthians 5:9–11, where he anticipates this sort of misunderstanding. He says there, “I wrote you in my letter not to associate with immoral people; I did not at all mean with the immoral people of this world, or with the covetous and swindlers, or with idolaters, for then you would have to go out of the world. But actually, I wrote to you not to associate with any so-called brother if he is an immoral person, or covetous,” et cetera. Paul, more than anyone who’s ever lived, has modeled the exact opposite kind of lifestyle. Paul was no monk! He traveled the known world, marching right into the middle of pagan society and depraved human culture, in order to preach the Gospel to every creature in obedience to the commission of Christ. This is the one who says he has become all things to all men, so that [he] may by all means save some (1 Cor 9:22). The Lord Jesus taught us that we are the light of the world, Matthew 5:14, and no one lights a lamp and puts it under a basket. We are to let our light shine before men so that they glorify God who is at work within us.
And besides the obvious necessity of evangelism—engaging in the ministry of reconciliation as ambassadors for Christ—in 1 Corinthians 10:25, Paul assumes the Corinthians will shop in the marketplace where the rest of the unbelieving city shopped, and in 10:27 he encourages believers to accept an unbeliever’s invitation to his home for dinner. So there is no sense in which the call to separation in 2 Corinthians 6:14 is a call to monasticism or isolation from the world.
So what is it then? It’s what we spoke about before. It’s not so much a geographical or spatial separation as much as a spiritual and moral separation. Now, the most common application of this text is that Christians should not marry non-Christians. And while Paul isn’t thinking about marriage in this text, certainly the principle would apply to marriage—for what more intimate of a spiritual partnership is there than marriage? If believers and unbelievers can’t do ministry together, it is certainly asking for trouble to bear the common yoke of marriage together. And while Paul says a Christian may not divorce an unsaved spouse in 1 Corinthians 7 (vv. 12–14), he also forbids entering into marriage unless both parties are “in the Lord” (v. 39).
So, while it applies to marriage, the most primary application is to partnership in worship and ministry. No Christian is to take up common spiritual cause with a non-Christian—even a non-Christian who calls themselves a Christian, but who denies their profession by their life or their doctrine. There can be no commingling of worship or of ministry among genuine regenerate Christians and false converts. Believers cannot take part in a worship service of an apostate church—such as a Kingdom Hall meeting, or Roman Catholic mass, or Eastern Orthodox liturgy. A true believer cannot stand together with an unbeliever in any form of evangelistic ministry. And they certainly cannot pray together. This is the primary application of this command. Pastor John comments, “[Satan] does not want to fight the church; He wants to join it as much as join it. When he comes against the church, it grows stronger: ‘the blood of the martyrs is the seed of the church.’ When he joins the church, it grows weaker. And undiscerning believers think that’s an evangelistic strategy and embrace it. What folly. It’s not an evangelistic strategy, it’s slow suicide. Truth and error cannot go together.  They are opposite in nature; they are pulling in opposite directions; they are headed toward opposite goals; they are motivated by opposite desires, and they’re controlled by enemy leaders. We have to separate from non-Christians in every activity that has anything to do with the advancement of the gospel.  They can have no part, except to be on the receiving end of our evangelism. Undiscerning believers who join in a common spiritual cause with unbiblical forms of Christianity or other false religions open the door wide to satanic infiltration and forfeit the blessing of God. Further, embracing those heretical systems falsely reassures their followers that all is well between them and God, when actually they are headed for eternal damnation” (Sermon; Commentary, 246–47).
And he’s absolutely right. The Lord Jesus tells us in Matthew 11:29 that coming to Him in saving faith is to “take [His] yoke upon [us],” as He is our Master. But those who bear Christ’s yoke cannot share it with those who, in unbelief, refuse to take His yoke upon themselves. As one commentator said, “Those who harness themselves together with unbelievers will soon find themselves plowing Satan’s fields” (Garland, 331).
Five Fundamental Differences (vv. 14b—16a)
So much, then, for the call for separation between believers and unbelievers. After laying out this principled prohibition, Paul then illustrates the diametrical opposition and essential incongruity between genuine believers and unbelievers by means of five rhetorical questions—each of which inquire of compatibility between a pair of things that are the absolute antithesis and opposite of one another. Look again with me at verses 14 to 16: “Do not be bound together with unbelievers; for what partnership have righteousness and lawlessness, or what fellowship has light with darkness? Or what harmony has Christ with Belial, or what has a believer in common with an unbeliever? Or what agreement has the temple of God with idols?” These rhetorical questions outline five fundamental differences between believers and unbelievers that illustrate the absurdity of their being yoked together in common spiritual cause.
I. Governed by Different Rules of Life
First, believers and unbelievers are governed by different rules of life. Paul asks, “What partnership have righteousness and lawlessness?” Righteousness speaks of obedience to the law of God, whereas lawlessness speaks of rebellion to the law of God. And Paul asks, “What partnership could obedience and rebellion to the same law have with one another?” They are diametrically opposed! They are total opposites!
So too, then, are believers and unbelievers, because the rule of life that governs the unbeliever is the rule of lawlessness—the rule of rebellion to the law of God. 1 John 3:4 says plainly that “Everyone who practices sin also practices lawlessness, and sin is lawlessness.” This is what characterizes the life of the unredeemed. You say, “But I know plenty of unbelievers and they don’t seem lawless to me. They actually seem like nice people!” But what is the greatest commandment in the law of God? “You shall love the Lord your God with all your heart, soul, mind, and strength.” And that is absolutely impossible to do apart from saving faith in Jesus Christ! 1 John 2:23 says, “Whoever denies the Son does not have the Father.” 1 John 5:10 says, “The one who does not believe God has made Him a liar, because he has not believed in the testimony that God has given concerning His Son.” Unbelievers in Jesus don’t love God; they show contempt for God every moment of their lives by calling Him a liar concerning His testimony to His Son. And therefore their life is characterized and governed by rebellion, by lawlessness. That’s why, Titus 2:14, Christ is said to have redeemed His people “from all lawlessness,” because that is the rule of our lives before we come to salvation. It’s why Christ, at the end of the age, calls those whom He will send out of His presence into hell forever, “You who practice lawlessness” (Matt 7:23).
But as believers, we are no longer governed by lawlessness, but by righteousness. Christ has become our righteousness through faith in the Gospel, 1 Corinthians 1:30. By God’s grace of imputation, we have become the righteousness of God in Christ, 2 Corinthians 5:21. And that justifying righteousness issues in progressive, practical righteousness. Romans 6:19 says, “For just as you presented your members as slaves to impurity and to lawlessness, resulting in further lawlessness, so now present your members as slaves to righteousness, resulting in sanctification.” That is what believers do! Those who are genuinely united to Christ in saving faith are governed—dominated—by the principle of righteousness as a rule of life. The true child of God delights in the law of God. We are eager to obey, and to root out all lawlessness from our lives.
How could there be any partnership—any sharing of common cause, common goals, common efforts—between those who are governed by antithetical rules of life?
II. Subjects of Different Kingdoms
Second, believers and unbelievers are subjects of different kingdoms. Paul’s second question is: “What fellowship has light with darkness?” And I say that these relate to different kingdoms because of Colossians 1:12–13, which says that God “rescued us from the domain of darkness, and transferred us to the kingdom of His beloved Son,” and thus “qualified us to share in the inheritance of the saints in Light.”
In Scripture, light represents knowledge and truth, holiness of life, and blessedness; whereas darkness represents ignorance and error, sinfulness, and misery (Hodge, 543–44). And so the unbelieving world is under bondage in the domain of darkness. The very essence of unbelief is, John 3:19, that though Light has come into the world, men loved the darkness rather than the Light. Unbelief, 2 Corinthians 4:4, is the darkness of having our minds blinded by the god of this world, so that we might not see the light of the Gospel of the glory of Christ. And unless God intervenes, the wretched end of all unbelievers is to be cast into hell, which is represented in Scripture as outer darkness (Matt 8:12).
And yet God Himself is Light, says 1 John 1:5, and in Him there is no darkness at all! And so He has called His people out of darkness and into His marvelous light, 1 Peter 2:9. Where there was the blindness of unbelief, God has shone into the hearts of believers the light of the knowledge of the glory of God in the face of Christ, 2 Corinthians 4:6. Therefore, Paul can say in Ephesians 5:8, “For you were formerly darkness, but now you are Light in the Lord,” and in 1 Thessalonians 5:5, “For you are all sons of light and sons of day. We are not of night nor of darkness.”
Now, who could possibly need to be told that there is nothing more incompatible and mutually exclusive than light and darkness? Where there is light, there is no darkness, and where there is darkness, there is no light. The presence of the one destroys the presence of the other. So how should we expect there to be any fellowship between light and darkness? To think that the children of light might partner together and have spiritual or ministerial fellowship with the children of darkness is as ludicrous and foolish as to expect it to be both light and dark in the same place at the same time (MacArthur, 249).
III. Ruled by Different Kings
And because believers and unbelievers are subjects of different kingdoms, they also, quite naturally, are ruled by different kings. In verse 15, Paul asks, “Or what harmony has Christ with Belial,” or Satan? The Lord Jesus Christ is the very embodiment of righteousness, while Satan is the embodiment of lawlessness. Christ is the ruler of the kingdom of light, while Satan is the ruler of the domain of darkness. Now let me ask you: What harmony exists between Christ and Satan?
The word “harmony,” is the Greek word sumphonesis, from which we get the word “symphony,” and so the translation “harmony” captures the concept well. The word has the sense of two parties working together in a coordinated way and on a common task (Guthrie, 352). But dear friends, do Christ and Satan agree on anything? Do they ever come together to make common cause? Absolutely not! They are fundamentally opposed to one another! Christ is the Way, the Truth, and the Life (John 14:6), while Satan is the father of lies and a murderer from the beginning (John 8:44), whose supreme dedication has always been to undermine the purposes of God. Even his name, Satan, means the Enemy, the Adversary. Philip Edgcumbe Hughes writes, “Between these two no harmony is possible, but only the deadliest antagonism” (248).
And every person in the world is ruled by one of these two different kings. Those who belong to the domain of darkness are ruled by the prince of darkness. Those who have been transferred to the kingdom of God’s beloved Son have been made to share in the inheritance of the saints in Light. Those who are outside of Christ are children of Satan; Jesus tells the Pharisees in John 8:44: “You are of your father, the devil.” But, John 1:12, to as many as received Christ, He gave them the right to become children of God. To expect that there can be spiritual or ministerial harmony between the children of God and the children of the devil—between the servants of these two kings who are violently opposed to one another—is as unthinkable and blasphemous as the Holy Son of God linking arms with Satan Himself in common spiritual cause!
IV. Possessed of Different Worldviews
Believers and unbelievers are governed by different rules of life, are subjects of different kingdoms, and ruled by different kings. A fourth fundamental difference between the regenerate and unregenerate is they are possessed of different worldviews. In the second part of verse 15, Paul asks plainly, “Or what has a believer in common with an unbeliever?”
And here Paul states the case plainly, and clarifies the fundamental opposition between the two parties by simply drawing attention to the names that designate them: believer, and unbeliever. X, and not-X. Christian, and non-Christian. There is no more basic a statement you can make than to say X can have no partnership with not-X.
A believer and an unbeliever are possessed of fundamentally different worldviews—of mutually exclusive ideologies—of radically opposed fundamental convictions. The believer puts all his faith, all his hope, all his trust in the person of Christ and in the promises of Scripture. The unbeliever puts his trust in himself, or in this world, or in the fruitless philosophies of man-made religion, and scoffs at the authority of God’s Word. The believer’s life revolves around Christ, and making much of His glory, magnifying His name throughout the world. The unbeliever’s life revolves around himself, making much of his own glory, and doing everything he can to make a name for himself in the world. The unbeliever craves the praise of man; the believer craves the reward of Christ. The unbeliever’s treasure is laid up on earth where moth and rust destroy; the believer’s treasure is reserved in heaven where it can never perish or fade.
And while it’s true that we share a common human nature, that we’re both made in the image of God, and we live in the same world, in everything that truly matters in life—our hope, our trust, our passions, our convictions—believers and unbelievers share nothing in common.
And the fifth fundamental difference that Paul outlines here we’ll save for next week, as that launches us into a whole study of how we as believers are the very temple of God itself, where the infinite and eternal God makes His dwelling place.
But what is the application of all that we’ve said? Well first, dear people, it is to be involved in ministry. The prohibition to minister alongside unbelievers assumes that Christians will be ministering in the first place! Go into your world and preach the Gospel to those whom the Lord has brought to you! But as you do, be sure to link arms only with those who are genuine believers, who truly know Christ. Don’t suggest that the Gospel doesn’t matter by proposing to do ministry with the enemies of the Gospel—with Mormons, Jehovah’s Witnesses, Roman Catholics, Eastern Orthodox, and all those who embrace theological liberalism and deny the fundamentals of the faith. Bear the yoke of Christian ministry. Pull that plow in service to Christ! But do not be yoked together with unbelievers."