1 Corinthians 14:21,22

²¹In 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.” ²²Therefore 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. 1 Corinthians 14:21,22