1 Corinthians 14:27 (KJV)

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.

If therefore the whole church be come together into one place, and all speak with tongues, and there come in those that are unlearned, or unbelievers, will they not say that ye are mad?

But if all prophesy, and there come in one that believeth not, or one unlearned, he is convinced of all, he is judged of all:

And thus are the secrets of his heart made manifest; and so falling down on his face he will worship God, and report that God is in you of a truth.

How is it then, brethren? when ye come together, every one of you hath a psalm, hath a doctrine, hath a tongue, hath a revelation, hath an interpretation. Let all things be done unto edifying.

But if there be no interpreter, let him keep silence in the church; and let him speak to himself, and to God.

Let the prophets speak two or three, and let the other judge.

If any thing be revealed to another that sitteth by, let the first hold his peace.

For ye may all prophesy one by one, that all may learn, and all may be comforted.

And the spirits of the prophets are subject to the prophets.