1 Corinthians 14:9-11

9It is the same for you. You must use your tongue to speak clearly. If not, nobody will understand what you are saying. You will only be speaking words into the air.

10There are many different kinds of languages in this world. They all mean something to the people who speak them.

11Perhaps somebody may speak to me in a language that I do not understand. Then we are like foreign people to each other.