That bears repeating.
"If he will not listen to the church, treat him as a pagan or tax collector." --Jesus
“If your brother or sister sins, go and point out their fault, just between the two of you. If they listen to you, you have won them over. But 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.’ If 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.
“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 that if two of you on earth agree about anything they ask for, it will be done for them by my Father in heaven. For where two or three gather in my name, there am I with them.” (Matthew 18:15-20)
If any of you has a dispute with another, do you dare to take it before the ungodly for judgment instead of before the Lord’s people? Or do you not know that the Lord’s people will judge the world? And if you are to judge the world, are you not competent to judge trivial cases? Do you not know that we will judge angels? How much more the things of this life! Therefore, if you have disputes about such matters, do you ask for a ruling from those whose way of life is scorned in the church? I say this to shame you. Is it possible that there is nobody among you wise enough to judge a dispute between believers? But instead, one brother takes another to court—and this in front of unbelievers!
The very fact that you have lawsuits among you means you have been completely defeated already. Why not rather be wronged? Why not rather be cheated? Instead, you yourselves cheat and do wrong, and you do this to your brothers and sisters. Or do you not know that wrongdoers will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor men who have sex with men nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God. And that is what some of you were. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God. (I Corinthians 6:1-11)