Matthew 18:15-18 (King James Version)
¹⁵Moreover if thy brother shall trespass against thee, go and tell him his fault between thee and him alone: if he shall hear thee, thou hast gained thy brother. 
¹⁶But if he will not hear thee, then take with thee one or two more, that in the mouth of two or three witnesses every word may be established. 
¹⁷And if he shall neglect to hear them, tell it unto the church: but if he neglect to hear the church, let him be unto thee as an heathen man and a publican. 
¹⁸Verily I say unto you, Whatsoever ye shall bind on earth shall be bound in heaven: and whatsoever ye shall loose on earth shall be loosed in heaven.

Luke 17:3-4
³Take heed to yourselves: If thy brother trespass against thee, rebuke him; and if he repent, forgive him. 
⁴And if he trespass against thee seven times in a day, and seven times in a day turn again to thee, saying, I repent; thou shalt forgive him.