1 Corinthians 14:9-11

Evangelical Heritage Version

⁹ So also with you: Unless you use your tongue to produce intelligible speech, how will anyone know what is being spoken? To be sure, you will be speaking only into the air.

¹⁰ There are perhaps ever so many kinds of languages in the world, and not one of them is without meaning. ¹¹ Accordingly, if I do not understand the language, I will be a foreigner to the speaker, and he will be a foreigner to me.