1 Corinthians 14:6 - 14:12
6 But now, brothers, if I come to you speaking in tongues, what will I profit you unless I speak to you either by way of revelation or of knowledge or of prophecy or of teaching? 7 Yet even lifeless things, either flute or harp, in producing a sound, if they do not produce a distinction in the tones, how will it be known what is played on the flute or on the harp? 8 For if the trumpet produces an indistinct sound, who will prepare himself for battle? 9 So also you, unless you utter by the tongue a word that is clear, how will it be known what is spoken? For you will be speaking into the air. 10 There are, perhaps, a great many kinds of sounds in the world, and none is without meaning. 11 If then I do not know the meaning of the sound, I will be to the one who speaks a barbarian, and the one who speaks will be a barbarian to me. 12 So also you, since you are zealous for spiritual gifts, seek to abound for the edification of the church.