The Sermon on the Mount contains an explicit statement of the relationship between Jesus and the law of Moses (Matt. 5:17, 3 Ne. 12:17). That statement was crucial in the Old World because how to live the law of Moses, particularly the purity provisions, constituted the bulk of religious observances performed by the individual. New World believers understood that the Atoning Messiah’s coming would change the law (Alma 34:13). Therefore, the people certainly needed to know about this predicted change. It is quite appropriate that Jesus, after completing his foundational teachings, which were the same in both hemispheres, answered the question uppermost in the Nephites’ minds.
He introduces the theme by alluding to a saying which the Nephites do not completely understand: “Therefore those things which were of old time, which were under the law, in me are all fulfilled. Old things are done away, and all things have become new” (3 Ne. 12:46–47; compare 2 Cor. 5:17). The Pauline context and that of 3 Nephi are very different. In Paul, it suggests individual transformation through the gospel. In 3 Nephi, it explains the transition from the law of Moses to the law of the gospel.