1 Corinthians 14:24

But prophecy is not for a sign merely, but is also suitable and useful for faith and for profit unto both classes. And this, if not directly, yet in the sequel he more clearly explained, saying, "he is reproved by all. For, if all prophesy," saith he, "and there come in one unbelieving or unlearned, he is reproved by all; he is judged by all; and thus are the secrets of his heart made manifest; and so he will fall down on his face and worship God, declaring that God is among you indeed." So that not in this only is prophecy greater, in its availing with each class, but also in its attracting the more shameless of the unbelievers. For it was not the same wonder, when Peter convicted Sapphira, which was a work of prophecy, and when he spake with tongues: but in the former case all shrank into themselves; whereas, when he spake with tongues, he got the credit of being even beside himself. This then he doth in respect of the tongues, showing that they not only deprive of glory, but also bring shame upon those who have them in the eyes of the unbelievers. But prophecy, on the contrary, is both free from reproach among the unbelievers, and hath very great credit and usefulness. For none will say in regard to prophesying, "they are mad;" nor will any one deride them that prophesy; but, on the contrary, will be astonished at and admire them. For "he is reproved by all," i. e., the things which he hath in his heart, are brought forward and shown unto all: now it is not the same thing for any one to come in and see one speaking in Persian and another in Syriac, and to come in and hear the secrets of his own mind; as whether he cometh in as a tempter and with evil mind, or sincerely; or that such and such a thing hath been done by him, and such another designed. For this is much more awful and more profitable than the other. […]

Then when he says, But if all prophesy, he shows that good follows from the gift of prophecy. In regard to this he does three things: first, he shows what follows through the good of prophecy, as to unbelievers; secondly, he shows how this follows …

But if all prophecy,.... That is, all that speak publicly in the church, not together, but in their order, one after another, as is hereafter directed: and there come in one that believeth not, or one unlearned; an unbeliever that has only the knowledge of his mother tongue, in which prophesying or preaching is used: he is convinced of all, he is judged of all; of all the prophets or preachers; they all reprove him, and detect his secret, as the Arabic version renders the words; and to the same purport the Ethiopic.

Note, Religious exercises in Christian assemblies should be such as are fit to edify the faithful, and convince, affect, and convert unbelievers. The ministry was not instituted to make ostentation of gifts and parts, but to save souls.

He is convicted by all - who speak in their turns, and speak to the heart of the hearers. He is judged by all - Everyone says something to which his conscience bears witness.