6 Dear brothers and sisters, if I should come to you speaking in an unknown language, how would that help you? But if I bring you a revelation or some special knowledge or prophecy or teaching, that will be helpful. 7 Even lifeless instruments like the flute or the harp must play the notes clearly, or no one will recognize the melody. 8 And if the bugler doesn't sound a clear call, how will the soldiers know they are being called to battle? 9 It's the same for you. If you speak to people in words they don't understand, how will they know what you are saying? You might as well be talking into empty space. 10 There are many different languages in the world, and every language has meaning. 11 But if I don't understand a language, I will be a foreigner to someone who speaks it, and the one who speaks it will be a foreigner to me. 12 And the same is true for you. Since you are so eager to have the special abilities the Spirit gives, seek those that will strengthen the whole church. 13 So anyone who speaks in tongues should pray also for the ability to interpret what has been said. 14 For if I pray in tongues, my spirit is praying, but I don't understand what I am saying.

Matthew Henry's Commentary on 1 Corinthians 14:6-14

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.