The Benefit of Tongues and Prophecy
to me, these verses have always seemed to contradict each other as to who tongues are for and who prophecy benefits the most. The Believers Bible Commentary explains that Paul is referring to two types of unbelievers here. Verse 22 refers to those who have rejected the Gospel, like Israel. The unbelievers in verses 23-25 are those who are open and receptive. Paul seems to make this kind of reference in other places of his writings as well.
