1 Corinthians 14:22-25

So then, tongues are not a sign for believers, but a miracle for unbelievers. Prophecy, on the other hand, is not for unbelievers, but a miracle sign for believers. If the entire church comes together and everyone is speaking in tongues, won’t the visitors say that you have lost your minds? But if everyone is prophesying, and an unbeliever or one without the gift enters your meeting, he will be convicted by all that he hears and will be called to account, for the intimate secrets of his heart will be brought to light. He will be mystified and fall facedown in worship and say, “God is truly among you!”