I told the brethren that the Book of Mormon was the most correct of any book on earth, and the keystone of our religion, and a man would get nearer to God by abiding by its precepts, than by any other book. Joseph Smith, History of the Church, 4:461
Skin-Color
God changed the Lamanite's skin from fair and delightsome [1] to black -- to make them less appealing to the Nephites. This is why Native Americans (who are the descendants of the Lamanites) have dark skin.
And he [God] had caused the cursing to come upon them [the Lamanites] ... wherefore, as they were white, and exceedingly fair and delightsome, that they might not be enticing unto my people the Lord God did cause a skin of blackness to come upon them. 2 Nephi 5:21
God said that any Nephite that mixed their seed with the dark-skinned Lamanites would receive the same cursing from God. (Their skin would be turned dark, too.)
And cursed shall be the seed of him that mixeth with their seed; for they shall be cursed even with the same cursing. And the Lord spake it, and it was done. 2 Nephi 5:23
If people dwindle in unbelief, their skin turns dark and they become a loathsome and filthy people, full of idleness and abominations.
And the angel said unto me: Behold these shall dwindle in unbelief. And it came to pass that I beheld, after they had dwindled in unbelief they became a dark, and loathsome, and a filthy people, full of idleness and all manner of abominations. 1 Nephi 12:22-23
The curse of dark skin is reversible, though. If dark-skinned people behave themselves, their skin will be lightened and they will become white and delightsome again. (This may take a few generations, however.) [2]
And then shall they rejoice; for they shall know that it is a blessing unto them from the hand of God; and their scales of darkness shall begin to fall from their eyes; and many generations shall not pass away among them, save they shall be a
whitepure and delightsome people. 2 Nephi 30:6
The descendants of Cain were black. [3]
And Enoch also beheld the residue of the people which were the sons of Adam; and they were a mixture of all the seed of Adam save it was the seed of Cain, for the seed of Cain were black, and had not place among them. Moses 7:22
The official LDS summary for 2 Nephi 5 prior to December 17, 2010:
The Nephites separate themselves from the Lamanites, keep the law of Moses, and build a temple -- Because of their unbelief, the Lamanites are cursed, receive a skin of blackness, and become a scourge unto the Nephites.
The LDS church revised the official summary for 2 Nephi 5 on December 17, 2010 to read:
The Nephites separate themselves from the Lamanites, keep the law of Moses, and build a temple--Because of their unbelief, the Lamanites are cut off from the presence of the Lord, are cursed, and become a scourge unto the Nephites.
If you believe in the Book of Mormon, your skin will turn white! (Well, it might take a few generations.)
In 1981 the Mormon church changed "white" to "pure" to soften the obvious racism in this verse.
Original version: "They shall be a white and delightsome people."
And here's the same verse after the 1981 change: "They shall be a pure and delightsome people."
Apparently, according to the Book of Moses, a black skin was the mark that God placed upon Cain in Genesis 4:15.
(Although the Book of Moses is not in the Book of Mormon, it is a part of Mormon scripture.)
