The key to an involved congregation is individual members committed to God and one another. Church members committed to involvement are characterized by several traits.

Humility. The person who is willing to do whatever is needed is someone who exhibits the spirit of Christ as expressed in Philippians 2.
Availability. This person recognizes that a top priority is being available to serve Christ by serving those around him or her.
Faithfulness. Having the ability to recognize a need, and then faithfully meet that need is a key to being a committed member.

If your life is marked by these qualities, you will be a person who is able to be greatly used to accomplish the work of God.