1 Corinthians 14:23-25

If, therefore, the whole church comes together and all speak in tongues, and outsiders or unbelievers enter, will they not say that you are out of your minds? But if all prophesy, and an unbeliever or outsider enters, he is convicted by all, he is called to account by all, the secrets of his heart are disclosed, and so, falling on his face, he will worship God and declare that God is really among you.