1 Corinthians 14:4-11

4He that speaks with a tongue edifies himself; but he that prophesies edifies [the] assembly.

5Now I desire that ye should all speak with tongues, but rather that ye should prophesy. But greater is he that prophesies than he that speaks with tongues, unless he interpret, that the assembly may receive edification.

6And now, brethren, if I come to you speaking with tongues, what shall I profit you, unless I shall speak to you either in revelation, or in knowledge, or in prophecy, or in teaching?

7Even lifeless things giving a sound, whether pipe or harp, if they give not distinction to the sounds, how shall it be known what is piped or harped?

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

9Thus also ye with the tongue, unless ye give a distinct speech, how shall it be known what is spoken? for ye will be speaking to the air.

10There are, it may be, so many kinds of voices in the world, and none of undistinguishable sound.

11If therefore I do not know the power of the sound, I shall be to him that speaks a barbarian, and he that speaks a barbarian for me.