Why is it wrong to take revenge?
Someone does you harm in some way and you want to get even; you want revenge. Taking revenge sounds like a good idea because it seems like a form of justice. You may be thinking if you don’t punish that person, nobody will. But justice and punishment needs to happen by people in authority, not by you. You’re afraid he will not get punished; he will get away with it. You’re right. Maybe he will get away with it, but people sometimes get away with doing bad things in this life. I know it’s not fair, but that’s life. It is more important to obey God than punish someone who has done bad things to us.
Do not repay anyone evil for evil. Be careful to do what is right in the eyes of everyone. If it is possible, as far as it depends on you, live at peace with everyone. Do not take revenge, my dear friends, but leave room for God’s wrath, for it is written: “It is mine to avenge, I will repay,” says the Lord.
Romans 12:17-19