According to Daniel Ludlow, the teachings of Jacob clearly indicate that the early Nephites considered baptism an essential ordinance of the gospel: "And he commandeth all men that they must repent, and be baptized in his name, having perfect faith in the Holy One of Israel, or they cannot be saved in the kingdom of God" (2 Nephi 9:23). Nephi also taught the necessity of baptism (2 Nephi 31:5-13). [Daniel H. Ludlow, A Companion to Your Study of the Book of Mormon, p. 139]
Many years after the lifetimes of Nephi and Jacob, the symbolism and significance of Christ's atonement and resurrection as they relate to the ordinance of baptism would become confused and even lost by the Nephites. The misunderstanding of this "doctrine of Christ" (2 Nephi 31:2) would necessitate covenant discourses by King Benjamin (Mosiah 2-5) and the prophet Abinadi (Mosiah 13-16). [Alan C. Miner, Personal Notes] [See the commentary on 2 Nephi 31:6; Mosiah 18:12-16]