John Calvin Commentary Romans 12:10

"In love of the brethren be tenderly affectioned one to another; in honor preferring one another;" — Romans 12:10 (ASV)

With brotherly love, etc. He could not find words adequate to express the ardor of that love with which we should embrace one another. For he calls it brotherly, and its emotion στοργὴν, affection, which, among the Latins, is the mutual affection that exists between relatives. And truly, this is the kind of affection we should have towards the children of God.

For this to be the case, he adds a precept very necessary for preserving benevolence: that everyone is to give honor to their brothers and not to themselves. For there is no poison more effective in alienating people's minds than the thought that one is despised.

But if by honor you are inclined to understand every act of friendly kindness, I do not strongly object; however, I approve more of the former interpretation. For just as there is nothing more opposed to brotherly harmony than contempt, which arises from haughtiness when each person, neglecting others, promotes themselves, so the best cultivator of love is humility, when everyone honors others.