Matthew 18:16-18

16But if he do not hear [thee], take with thee one or two besides, that every matter may stand upon the word of two witnesses or of three.

17But if he will not listen to them, tell it to the assembly; and if also he will not listen to the assembly, let him be to thee as one of the nations and a tax-gatherer.

18Verily I say to you, Whatsoever ye shall bind on the earth shall be bound in heaven, and whatsoever ye shall loose on the earth shall be loosed in heaven.