Mosiah

Mosiah opens Mormon's abridgment of the large plates, the fuller political and military record that runs alongside the small plates Nephi began. The record's own account of Mosiah's early reign is described by later Latter-day Saint editors as lost along with a portion of the original manuscript, so the book as it survives opens partway through the story, with King Benjamin, Mosiah's father, delivering a farewell address to his people before his death. The address is one of the most quoted passages in the Book of Mormon, urging service, humility and a covenant relationship with God, and it closes with the people entering into that covenant collectively.

The book then follows a separate group under Zeniff who had earlier resettled the land of Nephi, only to fall under Lamanite oppression. Within that community the prophet Abinadi confronts the wicked King Noah, is condemned and burned to death for his testimony, but not before converting a priest named Alma, who flees and founds a church among believers hiding at the Waters of Mormon. Mosiah closes by bringing these threads together: Alma's people and Zeniff's remnant both return to Zarahemla, and Mosiah replaces kingship with a system of judges.

Because Mosiah opens with its own opening chapters missing from the record as transmitted, it functions differently from every book before it: rather than introducing its protagonists, it assumes a reader is already partway into their story. Latter-day Saint tradition holds that the lost material was part of the original manuscript pages that went missing after being lent out during the translation process, and that Joseph Smith was directed not to retranslate the lost section, which is why Mosiah begins abruptly with Benjamin already an old king preparing to hand off his throne.

The book also marks a structural transition in Nephite governance, from hereditary kingship to a system of elected judges under Mosiah's reforms, a change the text frames as a response to the dangers of unrighteous kings such as Noah. Alma's founding of a church at the Waters of Mormon, independent of any king's authority, is read within the tradition as an early model for the religious community structure the rest of the Book of Mormon assumes, and Alma himself becomes the founding figure whose descendants narrate much of what follows.

Latter-day Saint editions today print explanatory chapter headings at the start of Mosiah to orient readers around this gap, since the surviving text supplies no in-text recap of what a hypothetical opening section, describing Mosiah's coronation and early reign, might once have covered before it was lost.