Charles Ellicott Commentary Romans 12:4

"For even as we have many members in one body, and all the members have not the same office:" — Romans 12:4 (ASV)

Members in one body.—This figure of the body and the members is worked out more fully in 1 Corinthians 12:12–27.

On verses 4, 5:

In the church there must be a graduation, a hierarchy, a division of labour, every one doing that for which he is best fitted, just as in the body one member has one office assigned to it, and another another. All Christians, viewed collectively, make up one body, the unity of which is supplied by their relation to Christ. Viewed individually, they stand to each other in the same sort of relation as the different limbs and organs of the natural body, as foot and hand, or hand and eye.