Therefore seems to mark a return to the main argument after Paul’s deviation in the previous two or three verses.

The clause the whole church assembles emphasizes that Paul is speaking of a full assembly of the Christians at Corinth. This clause may also be expressed as “all the believers meet together.”

All here refers to “everyone who can speak in tongues.” It does not mean that every person in church has the ability to speak ecstatically.

Outsiders: some commentators and translators believe that outsiders in this verse are different from the outsiders (Good News Bible‘s “ordinary people”) in verse 16. Revised English Bible even translates this one Greek word three different ways in verses 16, 23, and 24, seemingly indicating three separate groups of people. However, this Greek word is so unusual and distinctive that it is unlikely that Paul would use it so differently in this short passage. We therefore suggest that outsiders refers to the same people in all three verses, namely, Christians who do not have the gift of understanding and interpreting strange tongues.

Unbelievers means “non-Christians”; Paul was probably thinking of the pagans who formed most of the non-Christian population of Corinth.

Mad: Barrett notes that this word “does not mean, You are suffering from mental disease, but You are possessed,” that is, in the power of an evil spirit.

Quoted with permission from Ellingworth, Paul and Hatton, Howard A. A Handbook on Paul’s First Letter to the Corinthians, 2nd edition. (UBS Handbook Series). New York: UBS, 1985/1994. For this and other handbooks for translators see here .