If you are praising God with your spirit, how can one who finds himself among those who do not understanda say "Amen"1 to your thanksgiving,2 since he does not know what you are saying?
You may be giving thanks well enough, but the other man is not edified.318
I thank God that I speak in tongues more than all of you.
But in the church I would rather speak five intelligible words to instruct others than ten thousand words in a tongue.420
Brothers, stop thinking like children.5 In regard to evil be infants,6 but in your thinking be adults.
In the Law7 it is written: "Through men of strange tongues and through the lips of foreigners I will speak to this people, but even then they will not listen to me,"b8 says the Lord.
Tongues, then, are a sign, not for believers but for unbelievers; prophecy,9 however, is for believers, not for unbelievers.
So if the whole church comes together and everyone speaks in tongues, and some who do not understandc or some unbelievers come in, will they not say that you are out of your mind?1024
But if an unbeliever or someone who does not understandd comes in while everybody is prophesying, he will be convinced by all that he is a sinner and will be judged by all,
and the secrets11 of his heart will be laid bare. So he will fall down and worship God, exclaiming, "God is really among you!"12
What then shall we say, brothers?13 When you come together, everyone14 has a hymn,15 or a word of instruction,16 a revelation, a tongue17 or an interpretation.18 All of these must be done for the strengthening19 of the church.