16 Otherwise, if you have blessed only with the spirit, how can someone, in a state of ignorance, add an "Amen" to your blessing? For he does not know what you are saying.
17 In this case, certainly, you give thanks well, but the other person is not edified.
18 I thank my God that I speak in tongues for all of you.
19 But in the Church, I prefer to speak five words from my mind, so that I may instruct others also, rather than ten thousand words in tongues.
20 Brothers, do not choose to have the minds of children. Instead, be free of malice like infants, but be mature in your minds.
21 It is written in the law: "I will speak to this people with other tongues and other lips, and even so, they will not heed me, says the Lord."
22 And so, tongues are a sign, not for believers, but for unbelievers; and prophecies are not for unbelievers, but for believers.