Because Jesus is indeed the Christ, because he is the Eternal God, because salvation is in him and through his holy name and none other, and because these precious verities have been known and kept in the Nephite and Jaredite records, the Lord has promised that Nephi’s teachings on the Christ and his gospel will be preserved unto the last days (see 2 Nephi 33:10).
Thus through this means—because many of the descendants of Lehi (and of men and women from other branches of the house of Israel) will hearken to the words of the Book of Mormon (2 Nephi 3:23)—the message of Christ will go forth from generation to generation “as long as the earth shall stand.” Further, Joseph’s children, Ephraim and Manasseh, are destined to take the message of salvation through the Book of Mormon to all the nations of the earth. “And this gospel shall be preached unto every nation, and kindred, and tongue, and people” (D&C 133:36-37).