15 Well then, what shall I do? I will pray in the spirit, and I will also pray in words I understand. I will sing in the spirit, and I will also sing in words I understand. 16 For if you praise God only in the spirit, how can those who don't understand you praise God along with you? How can they join you in giving thanks when they don't understand what you are saying? 17 You will be giving thanks very well, but it won't strengthen the people who hear you. 18 I thank God that I speak in tongues more than any of you. 19 But in a church meeting I would rather speak five understandable words to help others than ten thousand words in an unknown language. 20 Dear brothers and sisters, don't be childish in your understanding of these things. Be innocent as babies when it comes to evil, but be mature in understanding matters of this kind.
21 It is written in the Scriptures : "I will speak to my own people through strange languages and through the lips of foreigners. But even then, they will not listen to me," says the Lord . 22 So you see that speaking in tongues is a sign, not for believers, but for unbelievers. Prophecy, however, is for the benefit of believers, not unbelievers. 23 Even so, if unbelievers or people who don't understand these things come into your church meeting and hear everyone speaking in an unknown language, they will think you are crazy. 24 But if all of you are prophesying, and unbelievers or people who don't understand these things come into your meeting, they will be convicted of sin and judged by what you say. 25 As they listen, their secret thoughts will be exposed, and they will fall to their knees and worship God, declaring, "God is truly here among you."
Matthew Henry's Commentary on 1 Corinthians 14:15-25
Commentary on 1 Corinthians 14:15-25
(Read 1 Corinthians 14:15-25)
There can be no assent to prayers that are not understood. A truly Christian minister will seek much more to do spiritual good to men's souls, than to get the greatest applause to himself. This is proving himself the servant of Christ. Children are apt to be struck with novelty; but do not act like them. Christians should be like children, void of guile and malice; yet they should not be unskilful as to the word of righteousness, but only as to the arts of mischief. It is a proof that a people are forsaken of God, when he gives them up to the rule of those who teach them to worship in another language. They can never be benefitted by such teaching. Yet thus the preachers did who delivered their instructions in an unknown tongue. Would it not make Christianity ridiculous to a heathen, to hear the ministers pray or preach in a language which neither he nor the assembly understood? But if those who minister, plainly interpret Scripture, or preach the great truths and rules of the gospel, a heathen or unlearned person might become a convert to Christianity. His conscience might be touched, the secrets of his heart might be revealed to him, and so he might be brought to confess his guilt, and to own that God was present in the assembly. Scripture truth, plainly and duly taught, has a wonderful power to awaken the conscience and touch the heart.