1 Corinthians 14:20 - 14:22
20 Brothers, do not be children in your thinking; rather in evil be infants, but in your thinking be mature. 21 In the Law it is written, “By men of strange tongues and by the lips of strangers I will speak to this people, and even so they will not listen to Me,” says the Lord. 22 So then tongues are for a sign, not to those who believe but to unbelievers; but prophecy is for a sign not to unbelievers but to those who believe.