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.