1 Corinthians 14:22

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.

Mark 16:17

These signs will accompany those who have believed: in My name they will cast out demons, they will speak with new tongues;

1 Corinthians 14:1

Pursue love, yet desire earnestly spiritual gifts, but especially that you may prophesy.

Acts 2:6-12

And when this sound occurred, the crowd came together, and were bewildered because each one of them was hearing them speak in his own language.

Acts 2:32-36

This Jesus God raised up again, to which we are all witnesses.

realizing the fact that law is not made for a righteous person, but for those who are lawless and rebellious, for the ungodly and sinners, for the unholy and profane, for those who kill their fathers or mothers, for murderers

Treasury of Scripture Knowledge

Summary

1 Corinthians 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.