1 Corinthians 14:20-22

WNT(i) 20 Brethren, do not prove yourselves to be children in your minds. As regards evil, indeed, be utter babes, but as regards your minds prove yourselves to be men of ripe years. 21 In the Law it stands written, "'BY MEN OF UNKNOWN TONGUES AND BY THE LIPS OF AN UNKNOWN NATION WILL I SPEAK TO THIS PEOPLE, BUT EVEN THEN THEY WILL NOT LISTEN TO ME', says the Lord." 22 This shows that the gift of tongues is intended as a sign not to those who believe but to unbelievers, but prophecy is intended not for unbelievers but for those who believe.