Social: The first organization of congregations has seven separate "churches." Each of these would be a specific congregation with separate priests and leaders. Where were they? The text says that they were "in the land of Zarahemla."
In Book of Mormon terms, this indicates the greater area attached to the city of Zarahemla rather than the city proper. Thus it is quite possible that the seven represented pre-defined communities structured by the current living arrangements. One congregation would be the city of Zarahemla and the immediately surrounding farming district. The other six were probably dependent towns or hamlets that were some distance from Zarahemla, but which looked to Zarahemla for political/religious leadership. Indeed, as we progress, we will see Alma traveling to different cities. These first churches were probably created along the city/town/hamlet boundaries.
The text indicates that those who wished to take upon themselves the name of Christ joined these churches. The taking of the name was Benjamin's covenant. While we do not know specifically of Alma also convenanted by the adoption of the name, it certainly makes sense to continue to promote the Benjamin covenant as well as Alma's baptism.
Translation:Note that we have in the text "the name of Christ, or of God." As has been indicated multiple times before, the Nephite conception of their Atoning Messiah was that he was equivalent to Jehovah, and therefore the same as their God.
In this passage the original sense of the Book of Mormon is retained, without the alteration that has been made to make the sense of it clearer to modern LDS who make distinctions that the Nephites did not understand. Of course we also understand Jesus as incarnate Jehovah, so there is no real difference in our understanding, only the problematic distinctions we make when we use God as an exclusive designator of the Father rather than Jehovah.
Mosiah 25:24
24 And they were called the people of God. And the Lord did pour out his Spirit upon them, and they were blessed, and prospered in the land.
Textual: There is no chapter break here in the 1830 edition. This verse is both an end and a setup for the next verse.
While this verse does end part of the story of the establishment of churches, the net social effect of that change comes in the next verse. Whether or not Mormon explicitly understood the creation of the churches as the enabler for the social divisions that followed we cannot tell. The next chapter, however, focuses precisely on those social divisions. Thus this verse sets up the contrast between the initial outpouring of the Spirit, and the religious contentions that will follow.