1 Corinthians 5:11
11 But now I have written unto you not to keep company, if any man that is called a brother be a fornicator, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner; with such an one no not to eat.
In his last letter (that is lost) Paul wrote to the Corinthian church not to company or mingle with fornicators. He explained what he didn’t mean in verse 10. Now he clarifies what he did mean.
That is any man that is called a brother who is involved in particular sins. By called he means anyone who bears the name brother. Paul lists the sins from verse 10 but adds two more: fornicator, covetous, idolater, railer, or drunkard. A railer is a verbally abusive person. It is the same word used in 1 Corinthians 6:10 but translated reviler.
Paul means the ones in the church who call themselves brothers. They were no not to eat with such a person. What does eat mean? It means to eat with them. Not to sit around the table in fellowship. Not to mingle with them as they continue living in their sin. Why, because they call themselves brothers, but are not living like brothers.