Paul says that if you are really thinking about other people, if you are really concerned about them, and if you are beginning to exercise the kind of love about which he spoke in the thirteenth chapter, you will recognize that people are hurting. So in your worship services you will not be trying to call attention to yourself as so many people do. But rather you will seek to do that which is helpful to them.
He brings in an illustration at this point about music. He talks about the flute and the harp, and then later on he speaks about the trumpet. He says there has to be something intelligible in order for music to make sense. If everybody just gets together with their instruments and plucks the strings, or blows on their horn, and nobody pays attention to an ordered score, it is not beneficial to anybody. It is cacophonous, and, as a matter of fact, it is horrible. Or if in battle somebody picks up a trumpet, and just blows on their trumpet and does not blow a recognizable tune that people can interpret, the soldiers are not going to know whether to go forward and charge or go backward and retreat. He says it is the same way in the worship service.
I suppose an illustration of that which comes a little bit closer to home is the way many of us sing. I love to sing, but I do not sing solos because I am not sure that it would be edifying to the church as a whole. Paul is saying that your service in the church ought to be helpful, and that it should provide strength, encouragement, and comfort to the body of Christ.
Having spoken about the value of prophecy where the church as a whole is concerned, in verse 13 the second thing he talks about is the beneficial effects of prophecy rather than of speaking in tongues for the individual himself. What he does here is contrast praying with his spirit and praying with his mind. The way many of us think, that contrast would be weighted on the side of the spirit because spiritual things are good. We therefore say that it is much better to pray with our spirit than to pray with our mind. Of course, what we mean by that is probably right. We mean that there is no use just saying words. We have to be in tune with God, and pray in the same way we worship. What we mean by that is right, but we are wrong if we contrast that kind of praying with praying with our mind.
Jesus said in John 4 that the true worshipers of God must worship in spirit and in truth (v. 24). It is interesting that He combined truth with worshiping in spirit. It must be a genuine heart worship, where the Spirit of God is bearing witness with our spirit. It has to operate on that level. But at the same time, it has to be according to truth, and truth involves content.
Paul’s point in 1 Corinthians 14 is that in prayer one’s spirit and one’s mind must function together. The same also goes for prophesying or preaching. We have such a danger in our time of indulging, especially in American Christianity, in what I call “contentless Christianity.” It is the kind of Christianity that often takes place in services where there seems to be a great deal of fire but not much light, a great deal of emotion but not much instruction. People will go away on an emotional experience, but when you ask them afterwards what it is they learned or what difference it is going to make in their lives because of the time they spent together in that particular form of worship, there is really very little to offer.
I think that is a terrible danger. If we get off into that kind of emotional experience apart from content, it is very easy to find ourselves performing in ways that are contrary to God’s revelation in His Word. We can say, “Well, I just feel that this particular direction is the right thing to do.” But that kind of thinking is always dangerous unless you can go back to the Word and say, “This is what the Word teaches, and as I try to take the Bible’s teaching and apply it to my life, it seems to me inescapable that it has to be applied in this way.” We must stress the Scripture again and again.
However, that is not to say that we should have content apart from an emotional response. People respond in different ways, but we are hard-hearted indeed if we can read these great truths in the Gospel of God’s love for us and His desire for our lives and not be emotionally moved by them. The point is that it should be the content of Scripture that moves us rather than simply indulging in that emotional experience alone. So prophecy in the sense of proclaiming the Word, teaching the Word, and applying the Word is not only beneficial for the church and should be practiced for that reason, but it is beneficial for the individual himself.

