"Moreover if your brother sins against you, go and tell him his fault between you and him alone. If he hears you, you have gained your brother.
Matthew 18:15
Surrounding context
18:14 Even so it is not the will of your Father who is in heaven that one of these little ones should perish.
18:15 "Moreover if your brother sins against you, go and tell him his fault between you and him alone. If he hears you, you have gained your brother.
18:16 But if he will not hear, take with you one or two more, that "by the mouth of two or three witnesses every word may be established.'