There are some very important teachings in the last chapters of the Book of Mormon, mostly from the writings and sermons of Mormon quoted by Moroni. Mormon’s teachings about charity (Moroni 7) and infant baptism (Moroni 8) are quoted frequently, and his account of the final depravity of the Nephites and Lamanites (Moroni 9) brings the history of Lehi’s descendants to a chilling conclusion.
And you know what’s amazing? Moroni never intended to include any of this! After finishing his father’s work of abridging the book of Ether, Moroni thought his mission was essentially done. He planned to write a little bit more, wrap up some loose ends, get a few things on the record, and call it a day (see Moroni 1:1-4).
Moroni had been a dedicated and devoted servant his whole life. Surely he had done enough and could relax now, right? But the Lord had other ideas. At some point, He prompted Moroni to include these other writings. Mormon and Moroni had seen our day (Mormon 8:12, 35; Moroni 10:29). They knew what we would be up against, and Moroni included valuable teachings we wouldn’t have had otherwise. Think of what we’d have missed out on if Moroni hadn’t been so diligent.