Matthew 18:15-17

“If your brother sins against you, go and rebuke him in private. If he listens to you, you have won your brother. But if he won’t listen, take one or two more with you, so that by the testimony of two or three witnesses every fact may be established. If he pays no attention to them, tell the church. But if he doesn’t pay attention even to the church, let him be like an unbeliever and a tax collector to you.