Bible reference (New Testament) Romans 12:17-21

Leave revenge to God. 

Romans 12

17 Never pay back evil with more evil. Do things in such a way that everyone can see you are honorable.

18 Do all that you can to live in peace with everyone.

19 Dear friends, never take revenge. Leave that to the righteous anger of God. For the Scriptures say,

“I will take revenge;
I will pay them back,”
says the Lord.
20 Instead,

“If your enemies are hungry, feed them.
If they are thirsty, give them something to drink.
In doing this, you will heap
burning coals of shame on their heads.”[b]

21 Don’t let evil conquer you, but conquer evil by doing good.