John Gill Commentary 1 Corinthians 12:19

"And if they were all one member, where were the body?" — 1 Corinthians 12:19 (ASV)

And if they were all one member

As all eye, or all ear, or all hand, or all foot: where were the body ? where would be the body?

It would not be a body consisting of such proper and suitable members, as it is now:

So if the community of the saints were either all ministers, or all hearers, there would be no body consisting of different persons to receive any benefit or usefulness from either. The church of Christ would not be that uniform, useful, and consistent community it is.