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.” [1] 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. 25 And thus the secrets of his heart are revealed. So he will fall down on his face and worship God, declaring that God is among you indeed.
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.