"But what if the person is my friend?"

But now I have written to you not to keep company with anyone named a brother, who is sexually immoral, or covetous, or an idolater, or a reviler, or a drunkard, or an extortioner —not even to eat with such a person.
1 Corinthians 5:11

Passages like this frequently elicit a cry of, “That’s not loving!”  When we are tempted to think that God’s Word is calling us to do what is unloving, without realizing it, we are claiming to be more loving than God is!  Impossible!

Why does God’s Word tell us to withdraw socially from those under church discipline, and from apostates(1)?  The goal is to take away what true Christians desire, namely: Christian fellowship.  If a person doesn’t miss Christian fellowship, it is a good bet that the person is not a Christian.  But a believer, cut off from the body of Christ, will eventually realize that he or she needs the fellowship and accompanied by the conviction of the Holy Spirit the person will repent.  Those who repent are to be gladly restored to fellowship. (1 Corinthians 5)

When we refuse to follow the clear biblical instruction about withdrawing from those under discipline and from apostates, rather than partnering with the Holy Spirit to urge them to repent, we encourage them in their sin.

Is this easy?  No.  Sometimes they are close friends or even family.  But if we truly love them, we must follow the clear teaching of Scripture in hopes that they will repent.

Two points of clarification:

1. We do not withdraw from people who are unsaved (see v.10 in this same chapter). 

2. We are to treat them kindly, calling them to repentance, but we must not socialize as though everything is just fine when it isn’t.

Footnote:
(1) An apostate is one who has professed faith in Christ, but who has turned away from the Lord and/or from His church.