For many years, scientists used to think that your appendix served no useful purpose. It’s a classic example of what’s called a vestigial organ – something which may once have been important for our evolutionary ancestors but is no longer needed and has all but withered away.
When Paul uses the image of the body to talk about the church, he knows that there will be some people who worry that they are the church’s appendix. But Paul insists that the body of Christ has no vestigial organs. Each of us has a gift and calling which the whole body needs if it is to remain healthy. (See 1 Cor 12:14-20) Just so, it is spiritually dangerous to act as though we didn’t need one another.
Modern science has found that, whatever its evolutionary history, the appendix does in fact serve important functions in our digestion and immune system. Our bodies and Christ’s body have no spare parts.