1 Corinthians 12:27 - Joseph Benson’s Commentary on the Old and New Testaments

Now ye Believers at Corinth; are the body of Christ A part of it, not the whole body; and members in particular That is, each believer is a particular member thereof, and ought to behave himself accordingly. This is the application of the foregoing allegory, which the apostle is thought by some to have formed on our Lord's words, Matthew 25:35-45. As if he had said, Ye believers are formed into one church or body, of which Christ is the head, soul, and ruler. And in the application he signifies, that “what he had said concerning the order, the situation, and the offices of the members of the human body, the union which subsists among them, and the care which they have of each other, and concerning the perniciousness of dissensions among its members, was all applicable to the members of the church of Christ. They were therefore to attend to the things he had written, that there might be no envy among them, nor discontent, nor arrogant preferring of themselves before others, but that in peace and love they might all promote each other's happiness.” Macknight.