In Zarahemla, we have record of only two major politico-religious trends. The first is the traditional Nephite way - the way of the gospel that has been the subject of all of the Nephite prophets. The second "way" is that of the world, with its costly apparel, social and economic stratification, and denial of the atoning Messiah. While the members of the church had apparently not denied the atoning Messiah, they were yet guilty of these other traits of the "other" religion. Since they were in danger of becoming too much like the world in their actions, this connection opens Alma to those who are not church members. He extends to them the invitation.
As his conclusion, he brings back the theme of the fruit if the tree of life. As was noted, this particular symbol was related to Lehi's dream among the Nephites, and was a symbol of accepting the atoning Messiah. It is to this that the non-members are invited, that they too might be filled with the joy of the gospel.
Textual: The end of this sermon to the congregation in Zarahemla ends a chapter for Mormon.