Matthew 18:15

15 Therefore if thy brother shall sin against thee, go and reprove him between thee and him alone; if he shall hear thee, thou hast gained thy brother.

Matthew 18:15 In-Context

13 And if so be that he finds it, verily I say unto you, he rejoices more of that one than of the ninety-nine who did not go astray.
14 Even so it is not the will of your Father who is in the heavens that one of these little ones should perish.
15 Therefore if thy brother shall sin against thee, go and reprove him between thee and him alone; if he shall hear thee, thou hast gained thy brother.
16 But 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.
17 And if he shall neglect to hear them, tell it unto the congregation {Gr. ekklesia – called out ones}; but if he neglects to hear the congregation, let him be unto thee as a worldly man and a publican.
The Jubilee Bible (from the Scriptures of the Reformation), edited by Russell M. Stendal, Copyright © 2000, 2001, 2010