1 Corinthians 14:20-22
20aBrothers, bdo not be children in your thinking; rather in evil cbe infants, but in your thinking be mature. 21In athe Law it is written, “bBy 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 1Lord. 22So then tongues are for a sign, not to those who believe but to unbelievers; but aprophecy is for a sign not to unbelievers but to those who believe.