In this passage, Paul shows that the church needed prophecy more than tongues. He begins by commanding the Corinthians to pursue love, but to desire spiritual gifts, especially the gift of prophecy. One reason for this is that one who speak in tongues does not speak to men because he is speaking a language that cannot be understood by those who hear him. However, one who prophesies speaks to men to build them up, to exhort them, and to console them. Furthermore, the one who speaks in tongues builds himself up, but the prophet builds the church up. However, Paul wishes that everyone spoke in tongues, but he wishes that everyone would prophesy more because the one who prophesies is greater than the one who speaks in tongues without an interpreter.
In verse 6, Paul begins to explain the limitations of the gift of tongues in more detail. If one speaks in tongues, he says, he will not profit the listeners unless he brings revelation, knowledge, prophecy, or teaching that they can understand. Then, he uses the example of lifeless things that make sound: if they do not make a sound that can be understood by a listener, they do not serve their intended purpose. Likewise, Paul says, tongues that are not understood by listeners are useless. However, Paul again commands the Corinthians to abound in spiritual gifts for the edification of the church. For this reason, in verse 13, Paul commands the Corinthians who speak in tongues to pray that they may interpret what they speak. The reason for this is that the mind should be used, as well as the spirit, so that a listener may be edified. Therefore, Paul would rather speak words that can be understood than words that cannot be understood.
In verse 20, Paul commands the church to be innocent in evil, but to be mature in their thinking. Then, he quotes a passage of Scripture that prophesies that God would speak to Israel with foreign languages, but would not be listened to by them. Paul concludes from this that tongues are a sign for unbelievers, but prophecy is a sign for believers. Therefore, if every church member speaks in tongues, unbelievers and those without the experience of listening to tongues will think that they are crazy. However, if everyone was to prophesy in the hearing of those same people, then they would be convicted, called to answer for their sins, would have their hearts revealed, and would worship God, because they would believe that God was among the church.