1 Corinthians 14
21 Ref In the law it is written, "By men of strange languages and by the lips of strangers I will speak to this people. Not even thus will they hear me, says the Lord."
22 Ref Therefore other languages are for a sign, not to those who believe, but to the unbelieving; but prophesying is for a sign, not to the unbelieving, but to those who believe.
23 Ref If therefore the whole assembly is assembled together and all speak with other languages, and unlearned or unbelieving people come in, won't they say that you are crazy?