It is obvious that Mormon is quoting when the text begins with “I, Alma.” In general, Mormon typically summarizes, but there are some texts where he felt it important to provide a full quotation. Typically, the quoted passages are important sermons. Thus, the very fact that we see “I, Alma” should warn the modern reader that Mormon felt that this was particularly important material.
As with many lessons in antiquity, Alma begins with a lesson from the past. He reminds his listeners that he is related to Alma the elder, who established a church in the land of Nephi and whose people that Jehovah delivered from bondage. There are two reasons for this introduction. The first is that it establishes Alma the younger’s credentials in connection to the church. Secondly, and more importantly, it is a story of deliverance from bondage. While the current church members in Zarahemla are not in bondage to the Lamanites, they are still in need of Jehovah’s deliverance.