I have written you in my letter not to associate with sexually immoral people—not at all meaning the people of this world who are immoral, or the greedy and swindlers, or idolaters. In that case you would have to leave this world. But now I am writing you that you must not associate with anyone who calls himself a brother but is sexually immoral or greedy, an idolater or a slanderer, a drunkard or a swindler. With such a man do not even eat. 1 Corinthians 5:9-11
Paul was never overly concerned about offending Christians who were doing the wrong thing. Several times he instructs the leaders to have nothing to do with certain people (2 Timothy 3:5, Titus 3:10) even telling Titus to sharply rebuke a particular group of people (Titus 1:13). Yet these days Christians often walking around on “egg shells” trying not to offend anyone in the mistaken belief that this is the most loving thing to do. Obviously, Paul didn’t think so. Love doesn’t stop us pointing out to our children their misdeeds. Rather it’s because we love them that we correct them.
However, it’s interesting that Paul makes a clear distinction between those people who are part of our Christian community and call themselves brothers, and “the people of this world”. Paul expects us to associate with people of this world, “otherwise we would have to leave this world.” Jesus’ prayer confirms this: “My prayer is not that you take them out of the world but that you protect them from the evil one” (John 17:15).
Paul teaches us that when it comes to immoral behaviour, our response to people depends on whether they are Christians. We only avoid those people who claim to be a Christian while living an immoral lifestyle.1 Corinthians