Why did Paul rebuke the Corinthians in 1 Corinthians 11 about the Lord's Supper?
Paul rebuked the Corinthians for abusing the Lord's Supper. Before the official Communion of Unleavened Bread and the cup, they held a potluck supper. The congregation spanned slaves to wealthy merchants, and the poorer members brought only what they could afford, which reflected the abuse.
Les explains that Paul had to upbraid the Corinthians because they were totally abusing the Lord's Supper. Before they would actually have what we would call the official Lord's Communion table of the Unleavened Bread and the wine or the cup, they would have a potluck supper. The Corinthian believers were a cross-section of society: a few Jews, more Gentiles, slaves and bond slaves at the bottom, and wealthy merchant men whose ships likely used Corinth as their home bay. In a potluck, people are people; those at the bottom echelon brought what they could afford, more or less the mundane and cheaper things. This social setting helps explain the abuse Paul addressed.