1 Corinthians 14:22

14:22 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.
-World English Bible

Other Translation

14:22 Wherefore tongues are for a sign, not to them that believe, but to them that believe not: but prophesying [serveth] not for them that believe not, but for them which believe.
-King James Version