Lehi quotes or paraphrases from the plates of brass to show where the opposition to Adam and Eve had originated. An angel of God fell from heaven and became the devil (v. 17). He “rebelled against [God], and sought to destroy the agency of man, which I, the Lord God had given him” (Moses 4:3). As revealed to Joseph Smith:
36 And it came to pass that Adam, being tempted of the devil— for, behold, the devil was before Adam, for he rebelled against me, saying, Give me thine honor, which is my power; and also a third part of the hosts of heaven turned he away from me because of their agency;
37 And they were thrust down, and thus came the devil and his angels. [D&C 29:36–37]
Because the devil was eternally miserable, he sought the misery of all mankind (v. 18). Thus, the saying, “misery loves company.” After Adam and Eve were driven out of the garden of Eden, the devil became the opposition to mankind’s happiness. “And he became Satan, yea, even the devil, the father of all lies, to deceive and to blind men, and to lead them captive at his will, even as many as would not hearken unto my voice” (Moses 4:4). Lehi explains more about Adam and Eve.