Get rid of all bitterness, rage, anger, harsh words, and slander, as well as all types of malicious behaviour. Instead, be kind to each other, tenderhearted, forgiving one another, just as God through Christ has forgiven you.
Ephesians 4.31-32 (NLT)

Never pay back evil for evil to anyone. Do things in such a way that everyone can see you are honourable. Do your part to live in peace with everyone, as much as possible.
Dear friends, never avenge yourselves. Leave that to God. For it is written,
“I will take vengeance;
I will repay those who deserve it,” says the Lord.

Instead, do what the Scriptures say:
“If your enemies are hungry, feed them.
If they are thirsty, give them something to drink,
And they will be ashamed of what they have done to you.”

Don’t let evil get the best of you, but conquer evil by doing good.
Romans 12.17-21 (NLT)

A good person produces good words from a good heart, and an evil person produces evil words from an evil heart. And I tell you this, that you must give an account on judgment day of every idle word you speak.
Matthew 12. 35-36 (NLT)