1 Corinthians 14:9

New King James Version

So likewise you, unless you utter by the tongue words easy to understand, how will it be known what is spoken? For you will be speaking into the air.

Cross References

1 Corinthians 14:10

There are, it may be, so many kinds of languages in the world, and none of them is without significance.

1 Corinthians 9:26

Therefore I run thus: not with uncertainty. Thus I fight: not as one who beats the air.