Matthew 18:12-17

How think ye? if any man have a hundred sheep, and one of them be gone astray, doth he not leave the ninety and nine, and go unto the mountains, and seek that which goeth astray? And if so be that he find it, verily I say unto you, he rejoiceth over it more than over the ninety and nine which have not gone astray. Even so it is not the will of your Father who is in heaven, that one of these little ones should perish. And if thy brother sin against thee, go, show him his fault between thee and him alone: if he hear thee, thou hast gained thy brother. But if he hear thee not, take with thee one or two more, that at the mouth of two witnesses or three every word may be established. And if he refuse to hear them, tell it unto the church: and if he refuse to hear the church also, let him be unto thee as the Gentile and the publican.