1 Corinthians 14:8

6But now, brothers, if I come to you speaking with other languages, what would I profit you unless I speak to you either by way of revelation, or of knowledge, or of prophesying, or of teaching?

7Even lifeless things that make a sound, whether pipe or harp, if they didn’t give a distinction in the sounds, how would it be known what is piped or harped?

8For if the trumpet gave an uncertain sound, who would prepare himself for war?

9So also you, unless you uttered by the tongue words easy to understand, how would it be known what is spoken? For you would be speaking into the air.

10There are, it may be, so many kinds of languages in the world, and none of them is without meaning.