1 Corinthians 14:22-25 So then the gift of tongues is for a sign, not to believers, but to unbelievers; but prophecy is not for unbelievers, but for those who believe.

MNT⁽ⁱ⁾ ²² So then the gift of tongues is for a sign, not to believers, but to unbelievers; but prophecy is not for unbelievers, but for those who believe. ²³ Accordingly, when the whole church assemblies, and everybody is speaking "with tongues," if there enter men unlearned or unbelieving, will they not say that you are mad? ²⁴ But if all are prophesying when an unlearned or unbelieving man enters, he is convicted in conscience by your speaker, he feels himself judged by all, ²⁵ and the secret depths of his heart are laid open. So he will fall upon his face and worship God, saying, "Of a truth, God is with you."