But now I am writing to you that you must not associate with anyone who claims to be a brother or sister but is sexually immoral or greedy, an idolater or slanderer, a drunkard or swindler. Do not even eat with such people. 1 Corinthians 5:11

kit: Love & Light by Createwings Designs (retired)

full passage:

Your boasting is not good. Do you not know that a little leaven leavens the whole lump? Cleanse out the old leaven that you may be a new lump, as you really are unleavened. For Christ, our Passover lamb, has been sacrificed. Let us therefore celebrate the festival, not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth. I wrote to you in my letter not to associate with sexually immoral people—not at all meaning the sexually immoral of this world, or the greedy and swindlers, or idolaters, since then you would need to go out of the world. But now I am writing to you not to associate with anyone who bears the name of brother if he is guilty of sexual immorality or greed, or is an idolater, reviler, drunkard, or swindler—not even to eat with such a one. For what have I to do with judging outsiders? Is it not those inside the church whom you are to judge? God judges those outside. “Purge the evil person from among you.” 1 Corinthians 5:6-13

Paul was talking about keeping the Body of Christ (comprised of our "brothers and sisters" in the Lord) healthy by removing from fellowship those who deliberately practice sin. The goal is always to help the person recognize that they need to repent of their sins so that they can be restored to fellowship rather than being deceived into thinking that God "doesn't mind" if His children behave in ways that He hates. One of the behaviors God particularly hates is that of bodily impurity (sexually), because our bodies are His temple. (1Thess. 4:1-8, Gal. 6:1, 1Cor. 5:4-5, 2Cor. 12:21, 1John 1:5-10, 1Cor. 6:18-20, Col. 3:5-11, Gal. 5:19-24, Eph. 4:17-32, 1Pet. 4:3-5, Rev. 21:7-8)