1 Corinthians 14:20

18I thank my God, I speak with other languages more than you all.

19However, in the assembly I would rather speak five words with my understanding, that I might instruct others also, than ten thousand words in another language.

20Brothers, don’t be children in thoughts, yet in malice be babies, but in thoughts be mature.

21In the law it is written, “By men of strange languages and by the lips of strangers I will speak to this people. They won’t even listen to me that way, says the Lord.”

22Therefore other languages are for a sign, not to those who believe, but to the unbelieving; but prophesying is for a sign, not to the unbelieving, but to those who believe.