1 Corinthians 14:4-11

4He that speaketh in a tongue edifieth himself; but he that prophesieth edifieth the church.

5Now I would have you all speak with tongues, but rather that ye should prophesy: and greater is he that prophesieth than he that speaketh with tongues, except he interpret, that the church may receive edifying.

6But now, brethren, if I come unto you speaking with tongues, what shall I profit you, unless I speak to you either by way of revelation, or of knowledge, or of prophesying, or of teaching?

7Even things without life, giving a voice, whether pipe or harp, if they give not a distinction in the sounds, how shall it be known what is piped or harped?

8For if the trumpet give an uncertain voice, who shall prepare himself for war?

9So also ye, unless ye utter by the tongue speech easy to be understood, how shall it be known what is spoken? for ye will be speaking into the air.

10There are, it may be, so many kinds of voices in the world, and no kind is without signification.

11If then I know not the meaning of the voice, I shall be to him that speaketh a barbarian, and he that speaketh will be a barbarian unto me.