1 Corinthians 14:9-11

New International Version - UK

⁹ So it is with you. Unless you speak intelligible words with your tongue, how will anyone know what you are saying? You will just be speaking into the air. ¹⁰ Undoubtedly there are all sorts of languages in the world, yet none of them is without meaning. ¹¹ If then I do not grasp the meaning of what someone is saying, I am a foreigner to the speaker, and the speaker is a foreigner to me.