When a family member professes to be a Christian and refuses to repent of known sin, other believing family members must continue to urge them to stop. Our goal in the conflict remains repentance for the sinner, reconciliation with God and man, and restoration to the fellowship of the church and the family.
This is why we must all take part in the discipline and restoration process described in Matthew 18: 15-17:
“If your brother sins against you, go and tell him his fault, between you and him alone. If he listens to you, you have gained your brother. But if he does not listen, take one or two others along with you, that every charge may be established by the evidence of two or three witnesses. If he refuses to listen to them, tell it to the church. And if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector."
Sometimes our loved ones refuse to cooperate putting us in a very difficult position as family members. We are family, and we are family of God and I believe that family of God has to take preeminence over earthly family. We must continue to press on out of love for the person and reverence for Christ.
We have been using the fictional case of Pat and Dan to illustrate our case. Pat a believing woman has hooked up with Dan who is an unbeliever. Despite all the warnings, pleadings, and revelations from Scripture Pat has decided that she doesn't believe the Bible means what it says in this case. She maintains she is a Believer, but thinks you take the Bible too literally. She believes her relationship with Dan is ok because she is happy and he is happy. They are now planning to get married. Pat has moved in with Dan to save money.
Initially, one person was encouraging Pat to repent and then a group of women were also involved in the process. When it became clear that Pat was not going to repent but instead deepened her involvement with Dad the church leaders stepped in.
In the final stage, Pat was warned by the leadership and the entire church as to the end result of her sin. Scripture was opened to her as to what it says about living in sexual immorality (1 Cor.6:13, 1Thess 4:3) and being yoked with an unbeliever (2 Cor. 6:14).
When the leaders of the church are confident there is nothing more to be said and it appears her heart has been so hardened that words are having no real impact the church must take the last formal step that is presented in Matt 18 and 1 Corinthians 5:
In the name of our Lord Jesus, when you are assembled, and I with you in spirit, with the power of our Lord Jesus, I have decided to deliver such a one to Satan for the destruction of his flesh, so that his spirit may be saved in the day of the Lord Jesus. 1 Corinthians 5:4-5 (NASB)
At this point, Pat will be turned over to her sin. The church will sorrowfully but intentionally let her go. In essence the church will release her and allow her to go down the path of destruction she has chosen for herself, eyes wide open and heart laid bare. Not out of anger or revenge but because this is the pattern set our for us in the Scriptures.
What this looks like is breaking off all social connection and keeping each encounter one of a continuing urge to repent. No casual conversations, no lunch dates, and no rescuing her if she calls in a jam or with a need. As hard as it is to bear, she must experience the full weight of the sin life she has chosen. This is a very hard thing to do, and those involved will soon realize their your own faith and trust in God growing in the process. Any conversation with her is to be about repentance.
The church must continue to pray for her; that God would grant her the gift of repentance and reconciliation.
She may or may not repent, and she may indeed marry the unbeliever and reap a harvest of misery as a result. The ministry of prayer and consistently reminding her of the love of God and His willingness to reconcile her to Himself upon her repentance is the best ministry the church can now have in her life.