The Apostle Paul
1 Corinthians 14:24ESV·traditional attribution

But if all prophesy, and an unbeliever or outsider enters, he is convicted by all, he is called to account by all,

John Calvin Reformed @genevareformer

24. But if all prophesy As he had previously showed them, how much more advantageous prophecy is to those that are of the household of faith (Galatians 6:10) than the gift of tongues, so he now shows that it would be useful also to those that are without. (1 Corinthians 5:13.) This is a most powerful consideration for showing the Corinthians their error.

Matthew Henry Presbyterian @wholebiblehenry

In this passage the apostle pursues the argument, and reasons from other topics; as, I. Tongues, as the Corinthians used them, were rather a token of judgment from God than mercy to any people (Co1 14:21): In the law (that is, the Old Testament) it is written, With men of other tongues and other lips will I speak to this people; and yet for all...

Commenting on 1 Corinthians 14:21-25

John Gill Reformed Baptist @doctorgill

And thus are the secrets of his heart made manifest,.... Not to the prophets, or preachers, or to the rest of the congregation, but to himself; the word preached being in the hands, and trader the influence, direction, and application of the Spirit of God, a discerner of the thoughts and intents of the heart; showing the plague and naughtiness of it, discovering the lusts...