“Repay no one evil for evil. Have regard for good things in the sight of all men. If it is possible, as much as depends on you, live peaceably with all men. Beloved, do not avenge yourselves, but rather give place to wrath; for it is written, “Vengeance is Mine, I will repay,” says the Lord”
(Romans 12:17-19 NKJV)

vengeance belongs to God not men

Romans 1-11 is generally viewed as the doctrinal part of the epistle, telling us what we need to know. Romans 12-16 is the practical part, telling us how we should then live. There is, of course, much overlap. So, how should we live?

Repay no one evil for evil: prohibits personal vengeance. Two other passages use this same expression (1 Thessalonians 5:15, and 1 Peter 3:9). See a similar thought in Romans 12:14.: “Bless those who persecute you; bless and do not curse.”

Have regard for good things in the sight of all men: calls us to think, to meditate beforehand, to give thought about the way in which we will act under provocation. Do not let the emotions of the moment influence you to do something you will later regret. The natural response to evil treatment is to pay it back in kind. This passage calls Christians to a higher, spiritual response.

If it is possible, as much as depends on you, live peaceably with all men: we cannot control the actions of others. Some are so contentious that it is impossible to be at peace with them. The word of the Lord will set a man against his father, a daughter against her mother, etc. (Matthew 10:34). We who are Christians, however, must avoid two extreme reactions: 1) we must never compromise the truth; 2) we must control our words and our actions. By self-control, some Christians have influenced hotheads to change their ways and to investigate the gospel.

Do not avenge yourselves...Vengeance is Mine, I will repay, says the Lord: vengeance belongs to the Lord; it is wrong to steal what is His alone. He knows what is best; He often works through others (including government) to avenge His own (Romans 13:1-7). Our kindness will yield better results (Romans 12:20) than our vengeance. Vengeance can destroy us with our enemy (Romans 12:21). To repay evil with evil does not to overcome evil but adds to it. We can best destroy an enemy by making him our friend.

– Rick Duggin