Dealing with a sinning brother

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.
But if he will not hear you, take with you one or two more, that 'by the mouth of two or three witness every word may be estabilished.'
And if he refuses to hear them, tell it to the church. But if he refuese even to hear the church, let him be to you like a heathen and a tax collector.
Assuredly, I say to you, whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaveb.
Again I say to you that if two of you agree on earth concerning anything that they ask, it will be done for them by My Father in heaven.
For where two or three are gathered together in My name, I am there in the midst of them.

MATTHEW 18:15-20 [The New King James Version]