Separation

In this Sunday's reading from Matthew 18:15-20, Jesus instructs us on how to deal with sin in the Church,

‘If another member of the church sins against you, go and point out the fault when the two of you are alone. If the member listens to you, you have regained that one. But if you are not listened to, take one or two others along with you, so that every word may be confirmed by the evidence of two or three witnesses. If the member refuses to listen to them, tell it to the church; and if the offender refuses to listen even to the church, let such a one be to you as a Gentile and a tax-collector. 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. Again, truly I tell you, if two of you agree on earth about anything you ask, it will be done for you by my Father in heaven. For where two or three are gathered in my name, I am there among them.’

Jesus knows that some people will just not listen and must be separated from his sheep, but he also knows that you can win back "Gentiles and tax-collectors", and that means that we are not to give up on former members who have fallen into sin, but we are to pray for them, and when we interact with them, we should let them know that they are welcome to return when they repent.