8. For if the trumpet gave an uncertain sound, who would prepare himself for war?
9. So also you, unless you uttered by the tongue words easy to understand, how would it be known what is spoken? For you would be speaking into the air.
10. There are, it may be, so many kinds of sounds in the world, and none of them is without meaning.
11. If then I don’t know the meaning of the sound, I would be to him who speaks a foreigner, and he who speaks would be a foreigner to me.
12. So also you, since you are zealous for spiritual gifts, seek that you may abound to the building up of the assembly.
13. Therefore let him who speaks in another language pray that he may interpret.
14. For if I pray in another language, my spirit prays, but my understanding is unfruitful.
15. What is it then? I will pray with the spirit, and I will pray with the understanding also. I will sing with the spirit, and I will sing with the understanding also.
16. Otherwise if you bless with the spirit, how will he who fills the place of the unlearned say the “Amen” at your giving of thanks, seeing he doesn’t know what you say?
17. For you most certainly give thanks well, but the other person is not built up.
18. I thank my God, I speak with other languages more than you all.
19. However 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.
20. Brothers, don’t be children in thoughts, yet in malice be babies, but in thoughts be mature.
21. In the law it is written, “By men of strange languages and by the lips of strangers I will speak to this people. Not even thus will they hear me, says the Lord.”
22. Therefore 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.
23. If therefore the whole assembly is assembled together and all speak with other languages, and unlearned or unbelieving people come in, won’t they say that you are crazy?
24. But if all prophesy, and someone unbelieving or unlearned comes in, he is reproved by all, and he is judged by all.