So though tongues are a sign for unbelievers, in at least the ways that have been here discussed, it is in this context that Paul has indicated that prophecy is for believers. How and why is this so? It is because prophecy serves to strengthen the church, which, by definition, are those that call Jesus Lord. It is those that call Jesus Lord who constitute the church, and therefore it is they who are the believers.
An unbeliever is not a component of the church, so they are not necessarily going to be concerned with making the Creator God’s kingdom present, though they may be physically present in the assembly (attending a church service is distinct from being a member of the entity that is understood as the body of Christ). The activity of prophecy however, because all are encouraged to participate without regard to position or status or honor (with no divisions at the table as befitting the messianic banquet which the church is called to model), should make a substantial impression on the unbeliever, which is something that will be addressed by Paul.
The twenty-third verse begins with “So if the whole church comes together and all speak in tongues” (1 Corinthians 14:23a). Stopping right there, it must be said that this would be quite the unusual event. It would be well outside the normal range of religious experience to have the entire assembly of an association demonstrating glossolalia. In the recorded history of this type of activity, the ecstatic utterances associated with the idea of being possessed by the spirit of a god, it was always a limited occurrence. As one understands that honor was a limited good, and that honor would accrue to the individual or individuals said to be employed by the god for communication that was in need of interpretation, it is more than sensible that the activity would be a limited to a select few individuals and would not occur prolifically or haphazardly. Such a thing would be quite novel.
Now if speaking in tongues was being used to create a spiritual hierarchy within the kingdom of the covenant God, this makes it possible to easily comprehend why there may have been a desire on the part of each person to engage in the practice, especially if this was the very Creator God, who had inhabited physical form in the person of Jesus of Nazareth, now speaking through another person by His Spirit.
If the Creator God had taken human form in the person of His Messiah, and if that Messiah had been resurrected from the dead and was being proclaimed as having received all power and all authority as Lord of all, and if that God was now speaking through another human by means of ecstatic utterances, then it is not at all difficult to understand why an entire congregation would have wanted to be viewed as the human vessel somehow inhabited by that God. If one thinks along these lines, and if this way of thinking represents reasonable speculations, then one is not left to wonder at the particular elevation of those that spoke in tongues.