Matthew 18 - ESV

If your brother sins against you, go and tell him his fault, between you and him alone. If he listens to you, you have gained your brother.

For where two or three are gathered in my name, there am I among them.

Then Peter came up and said to him, “Lord, how often will my brother sin against me, and I forgive him? As many as seven times?” Jesus said to him, “I do not say to you seven times, but seventy-seven times.”