1 Corinthians 14:7-9

New Century Version

⁷ It is the same as with lifeless things that make sounds—like a flute or a harp. If they do not make clear musical notes, you will not know what is being played. ⁸ And in a war, if the trumpet does not give a clear sound, who will prepare for battle? ⁹ It is the same with you. Unless you speak clearly with your tongue, no one can understand what you are saying. You will be talking into the air!