1 Corinthians 14:6

14:6 Now, brothers and sisters, if I come to you speaking in tongues, how will I help you unless I speak to you with a revelation or with knowledge or prophecy or teaching?

1 Corinthians 14:9

14:9 It is the same for you. If you do not speak clearly with your tongue, how will anyone know what is being said? For you will be speaking into the air.

1 Corinthians 14:21

14:21 It is written in the law: “By people with strange tongues and by the lips of strangers I will speak to this people, yet not even in this way will they listen to me,” says the Lord.