1 Corinthians 14:8-10

New International Version - UK

⁸ Again, if the trumpet does not sound a clear call, who will get ready for battle? 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.