Alma the Elder established a covenant community around 140 BC at the Waters of Mormon in the land of Nephi (Mosiah 18:17–18). When his group rejoined the Nephites in Zarahemla after 120 BC, King Mosiah "granted unto Alma that he might establish churches throughout all the land of Zaramehla; and gave him power to ordain priests and teachers over every church" (Mosiah 25:19). Soon "there were seven churches in the land of Zarahemla" (Mosiah 25:23). By about 83 BC, however, Alma the Younger had to once again "establish the order of the church in the city of Zarahemla" (Alma 6:4). Initially, "many of the rising generation" in the land of Zarahemla had forgotten or "could not understand the words of king Benjamin" and several of them would not be baptized (Mosiah 26:1, 4). Dissensions arose "among the brethren," and some people, eventually including Alma the Younger and the sons of Mosiah, "deceived many with their flattering words" (Mosiah 26:6; 27:8). Some dissenters were excommunicated (Mosiah 26:36), and the unbelievers began persecuting members of the church (Mosiah 27:1).
Book of Mormon Central, "Why Did Alma Need to ‘Establish the Order of the Church’ in Zarahemla Again? (Alma 6:4)," KnoWhy 113 (June 2, 2016).