<p>14:17 <i>For you truly give thanks well, but the other is not edified</i>- Again, Paul is being generous. If they were uttering unintelligible sounds and calling that 'prayer', acting just as the surrounding religious cults did, then they were hardly to be commended for praying well. So I think Paul effectively means us to read in an ellipsis: 'You may think that you truly give thanks well, but you would have to admit that the other is not edified'. And the whole argument turns around whether our actions are building others up or not. Paul's whole approach here is masterful, and should be given due weight by those who believe that God's truth is best served by a belligerent, confrontational approach, ever seeking to set up a much headlined showdown between truth and error.</p>