God's Four-step Program In Confronting

Step 4. If the person continues in willful sin and refuses to deal with it, he or she is to be excluded from the fellowship. That is the meaning of the phrase “let him be to you like a heathen and a tax collector” (Matt 18:17). 

But proceed with great caution. Before you start running around trying to see who should be kicked out of the fellowship, remember that it is God's heart to bring people in to His family, not to exclude them. 

Only in one extremely rare case in the New Testament do we see a member of the body of Christ being cast out of the fellowship because of a refusal to deal with overt sin (although in Acts 5, Ananias and Sapphira were struck dead for their sin). In Corinth, a young man was committing sexual immorality with his father's wife. Some commentators believe that the father had married again, and the young man had a relationship with the father's second wife. Other commentators hint that the sin involved an incestuous relationship with the son's own mother. 

Regardless, the apostle Paul instructed the church to “deliver such a one to Satan for the destruction of the flesh, that his spirit may be saved in the day of the Lord Jesus” (1 Cor 5:5). Even in this extreme situation, however, Paul's intent was not simply to punish the offending parties by excommunication. Paul's drastic steps were disciplinary in nature, intended to bring the fellow to a place of repentance so his soul could be saved. Later, in 2 Cor 2:5-11, Paul reminded the fellowship that it was time to restore the brother who was under church discipline. (See also Gal 6:1.)