9. Similarly, if you, because of speaking in tongues, do not utter intelligible speech, how will anyone know what is being said? For you will be talking to the air.
10. It happens that there are many different languages in the world, and none is meaningless;
11. but if I do not know the meaning of a language, I shall be a foreigner to one who speaks it, and one who speaks it a foreigner to me.
12. So with yourselves: since you strive eagerly for spirits, seek to have an abundance of them for building up the church.
13. Therefore, one who speaks in a tongue should pray to be able to interpret.
14. [For] if I pray in a tongue, my spirit is at prayer but my mind is unproductive.
15. So what is to be done? I will pray with the spirit, but I will also pray with the mind. I will sing praise with the spirit, but I will also sing praise with the mind.
16. Otherwise, if you pronounce a blessing [with] the spirit, how shall one who holds the place of the uninstructed say the “Amen” to your thanksgiving, since he does not know what you are saying?
17. For you may be giving thanks very well, but the other is not built up.
18. I give thanks to God that I speak in tongues more than any of you,
19. but in the church I would rather speak five words with my mind, so as to instruct others also, than ten thousand words in a tongue.
20. Brothers, stop being childish in your thinking. In respect to evil be like infants, but in your thinking be mature.
21. It is written in the law:“By people speaking strange tonguesand by the lips of foreignersI will speak to this people,and even so they will not listen to me,says the Lord.”
22. Thus, tongues are a sign not for those who believe but for unbelievers, whereas prophecy is not for unbelievers but for those who believe.