Babies make noises. We do not properly understand them, but they are the only language through which they can express their deep feelings. In time, the child hears and repeats words that always mean the same things, associating them with specific people, objects, actions and desires. It is an essential process to enable mature communication, without which constructive interaction and community integration is very difficult.
 
Paul had implied that the spiritual gift of speaking in tongues was like the newborn communication (1 Corinthians 13:11). That kind of intimate conversation should not be forbidden (1 Corinthians 14:39); indeed Paul wished that they all shared their hearts with the Lord (1 Corinthians 14:5). But the sounds could not make any sense to unbelievers, except to indicate that believers might have a deep personal relationship with God. But it was not gospel communication - because it could not clearly describe the need for salvation, the way of salvation and the response that is necessary.
 
Clarity matters. God uses words to define every truth, including the gospel. The task of the church is to communicate gospel truth to the world, which is in rebellion against God. But unless the message is clear, people cannot understand that the Lord is calling them to repent and believe in Jesus (Acts 2:38). Instead they will dream up their own gospel, which cannot save. So Paul urged the Corinthian church to grow up. They should focus their times of meeting together on sharing God's Word, so that the whole church could grow and that unbelievers might grasp the gospel and be saved.
 
The gospel is not an art form for personal interpretation. It is a message, in words, which precisely describes God's salvation work. Unless sinners know that God commands them to repent and receive Jesus as Lord, how can they enter into salvation? Discipleship demands that clarity too. Unless we know what pleases and offends our Father, how can we be obedient? Art and music invite us to create our own experience. By contrast, the gospel commands us to understand exactly what God is saying, agree with Him and respond in repentance and faith, verbally admitting that we belong to Christ (Romans 10:9-10). An undefined gospel is no gospel at all because it is what we want it to be – as opposed to accepting God's truth for what it is. After all, it is His Good News and not our best ideas! The gospel is no longer a mystery, except to those who have never heard it clearly.