John Calvin Commentary Romans 12:13

"communicating to the necessities of the saints; given to hospitality." — Romans 12:13 (ASV)

Communicating to the necessities, etc. He returns to the duties of love, the chief of which is to do good to those from whom we expect the least recompense. Since it commonly happens that those who are more than others burdened by need and require help are especially despised (for the benefits conferred on them are regarded as lost), God recommends them to us in a special manner.

It is indeed only then that we prove our love to be genuine, when we relieve needy fellow believers for no other reason than exercising our benevolence.

Now, hospitality is not one of the least acts of love—that is, the kindness and generosity shown towards strangers, for they are, for the most part, lacking everything, being far away from their friends. He therefore distinctly recommends this to us. Therefore, we see that the more neglected anyone commonly is by people, the more attentive we should be to their needs.

Observe also the appropriateness of the expression, when he says that we are to communicate to the necessities of the saints; by which he implies that we should relieve the needs of fellow believers as if we were relieving our own selves. And he commands us to assist especially the saints: for though our love should extend to the whole human race, yet it should embrace with special feeling the household of faith, who are united to us by a closer bond.