Now that Mormon has set the stage for the miraculous beginnings of the preaching of the gospel, he rapidly comes to the conclusion. Many are converted and the church is established. Mormon gives us no details, because he isn’t interested in the details of maintaining the organization of the church, but rather in the changing of hearts that allow for the establishment of the church.
As we see Mormon’s editorial selection of themes, he focuses on this change of heart. Repentance, rather than enduring in the faith, is Mormon’s message. It is quite probably a function of his world where the gospel was being rejected, and the competing religion was dominant both spiritually and militarily. Mormon lived in a world where the most important message was turning to God, not the intricacies of developing priestly bureaucracies to maintain a church.