Matthew 18:16-18

16But if they will not listen, take one or two others along, so that ‘every matter may be established by the testimony of two or three witnesses.’

17If they still refuse to listen, tell it to the church; and if they refuse to listen even to the church, treat them as you would a pagan or a tax collector.

18“Truly I tell you, whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven.