9 So if you speak in a way no one can understand, what's the point of opening your mouth? 10 There are many languages in the world and they all mean something to someone. 11 But if I don't understand the language, it's not going to do me much good. 12 It's no different with you. Since you're so eager to participate in what God is doing, why don't you concentrate on doing what helps everyone in the church? 13 So, when you pray in your private prayer language, don't hoard the experience for yourself. Pray for the insight and ability to bring others into that intimacy. 14 If I pray in tongues, my spirit prays but my mind lies fallow, and all that intelligence is wasted.

15 So what's the solution? The answer is simple enough. Do both. I should be spiritually free and expressive as I pray, but I should also be thoughtful and mindful as I pray. I should sing with my spirit, and sing with my mind. 16 If you give a blessing using your private prayer language, which no one else understands, how can some outsider who has just shown up and has no idea what's going on know when to say "Amen"? 17 Your blessing might be beautiful, but you have very effectively cut that person out of it. 18 I'm grateful to God for the gift of praying in tongues that he gives us for praising him, which leads to wonderful intimacies we enjoy with him. I enter into this as much or more than any of you. 19 But when I'm in a church assembled for worship, I'd rather say five words that everyone can understand and learn from than say ten thousand that sound to others like gibberish.

Matthew Henry's Commentary on 1 Corinthians 14:9-19

Commentary on 1 Corinthians 14:6-14

(Read 1 Corinthians 14:6-14)

Even an apostle could not edify, unless he spoke so as to be understood by his hearers. To speak words that have no meaning to those who hear them, is but speaking into the air. That cannot answer the end of speaking, which has no meaning; in this case, speaker and hearers are barbarians to each other. All religious services should be so performed in Christian assemblies, that all may join in, and profit by them. Language plain and easy to be understood, is the most proper for public worship, and other religious exercises. Every true follower of Christ will rather desire to do good to others, than to get a name for learning or fine speaking.

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.