Albert Barnes on Romans 12:4

For. This word here denotes a further illustration or proof of what he had just before said. The duty to which he was exhorting the Romans was, not to be unduly exalted or elevated in their own estimation. In order to produce proper humility, he shows them that God has appointed certain orders or grades in the church; that all are useful in their proper place; that we should seek to discharge our duty in our appropriate sphere; and thus that due subordination and order would be observed. To show this, he introduces a beautiful comparison drawn from the human body. There are various members in the human frame; all useful and honourable in their proper place; and all designed to promote the order, and beauty, and harmony of the whole. So the church is one body, consisting of many members, and each is fitted to be useful and comely in its proper place. The same comparison he uses with great beauty and force in 1Cor 12:4-31; also Eph 4:25 Eph 5:30. In that chapter the comparison is carried out to much greater length, and its influence shown with great force.

Many members. Limbs, or parts; feet, hands, eyes, ears, etc., 1Cor 12:14,15.

In one body. Constituting one body; or united in one, and making one person. Essential to the existence, beauty, and happiness of the one body or person.

The same office. The same use or design; not all appointed for the same thing; one is to see, another to hear, a third to walk with, etc., 1Cor 12:14-23.

(q) "many members" 1Cor 12:4,12