John Calvin Commentary Romans 12:18

"If it be possible, as much as in you lieth, be at peace with all men." — Romans 12:18 (ASV)

If it be possible, etc. Peaceableness, and a life so ordered as to make us beloved by all, is no common gift in a Christian. If we desire to attain this, we must not only be equipped with perfect uprightness but also with very courteous and kind manners, which can not only win over the just and the good but also produce a favorable impression on the hearts of the ungodly.

But here two cautions must be stated: We are not to seek to be held in such esteem that we refuse to endure the hatred of anyone for Christ, whenever it may be necessary. And indeed, we see that there are some who, though they make themselves friendly to all by the pleasantness of their demeanor and peaceful disposition, are yet hated even by their closest connections because of the gospel.

The second caution is that courteousness should not degenerate into mere compliance, leading us to flatter men's vices for the sake of preserving peace. Since, then, it is not always possible to have peace with all people, he has added two qualifications by way of exception: If it be possible, and, as far as you can. But we are to conclude from what piety and love require, that we are not to violate peace, except when compelled by either of these two necessities.

For, to maintain peace, we ought to bear many things, pardon offenses, and graciously relax the full strictness of the law; and yet in such a way that we are prepared, whenever necessity requires, to fight courageously: for it is impossible for Christ's soldiers to have perpetual peace with the world, whose prince is Satan.