Lesson of the brother's trespasses/the process of excommunication

Matt 18:14 Even so it is not the will of your Father which is in heaven, that one of these little ones should perish.

Matt 18:15 Moreover 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. Luke 17:3 Take heed to yourselves: If thy brother trespass against thee, rebuke him; and if he repent, forgive him.

Matt 18:16 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 [1]. 17 And 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.

Matt 18:18 Verily 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.

Matt 18:19 Again I say unto you, That if two of you shall agree on earth as touching any thing that they shall ask, it shall be done for them of my Father which is in heaven. 20 For where two or three are gathered together in my name, there am I in the midst of them.

[1]Deuteronomy 19:15 One witness shall not rise up against a man for any iniquity, or for any sin, in any sin that he sinneth: at the mouth of two witnesses, or at the mouth of three witnesses, shall the matter be established.