God declares to us that we are Christ's Body, and being a part of something that big and that important has enormous responsibilities. Note what Paul says:
I Corinthians 12:27 Now you are the body of Christ, and members individually.
You and I are each individual pieces, parts, members of Christ's Body. And as a member of His Body, we have shared responsibilities; to accomplish His plan we each must do what we were made to do! The Body of Christ is complex, made of many individual parts, each with a special job to do.