1 Corinthians 14:21-23

ACV(i) 21 In the law it is written, In other tongues and in other lips I will speak to this people, and not even so will they hear me, says the Lord. 22 Therefore tongues are for a sign, not to those who believe, but to the unbelieving. But prophesying is not to the unbelieving, but to those who believe. 23 If therefore the whole congregation comes together in the same place, and all speak in tongues, and unlearned or unbelieving men come in, will they not say that ye are mad?