The prophet Lehi knew many mysteries regarding the Lord’s purposes for the people of this world. This passage of the Book of Mormon was the first to touch upon this in no other way mentioned in the Bible. Some of these are also written about in the Book of Moses and Abraham. These are my personal “spiritual translations,” pray for your own confirmation.
18 And because he had fallen from heaven, [lost his glory] and had become miserable [restricted] forever, he sought also the misery of all mankind. Wherefore, he said unto Eve, yea, even that old serpent, [former being of light] who is the devil, who is the father of all lies, wherefore he said: Partake of the forbidden fruit [forbidden knowledge], and ye shall not die, but ye shall be as God, knowing good and evil. [a mystery]
19 And after Adam and Eve had partaken of the forbidden fruit they were driven out of the garden of Eden, [a place of God] to till the earth. [mortality]
20 And they have brought forth children; yea, even the family of all the earth. [the seed of Adam in a covenant world]
21 And the days [life] of the children of men [seed of men] were prolonged, [an extention] according to the will of God, that they might repent while in the flesh; [come to Him] wherefore, their state [estate] became a state of probation, [2nd] and their time [time of their judgment] was lengthened, according to the commandments which the Lord God gave unto the children of men. For he gave commandment that all men must repent [choose God]; for he showed unto all men that they were lost, because of the transgression of their parents. [All of these were without salvation because of the turning from God by their forebears.]
22 And now, behold, if Adam had not transgressed [deviated from the course] he would not have fallen [condescended], but he would have remained in the garden of Eden. [The place close to God] And all things which were created must have remained in the same state [estate] in which they were after they were created; and they must have remained forever, and had no end.
23 And they would have had no children; [bore children in mortality] wherefore they would have remained in a state of innocence, [without the law] having no joy, [the knowledge of God] for they knew no misery; [restricted] doing no good, for they knew no sin. [must first know sin to be made clean and exalted in Christ]
24 But behold, all things have been done in the wisdom [knowing the beginning from the end] of him who knoweth all things.
25 Adam fell [condescended] that men might be; [become holy] and men are, that they might have joy. [receive a fullness of their creation]
26 And the Messiah cometh in the fulness of time, [full-filling of prophecy] that he may redeem the children of men from the fall. [The mortal world is a dissension of glory, a state of uncleanliness.] And because that they are redeemed from the fall they have become free forever, knowing good from evil; to act for themselves [God’s way for Eternal Life] and not to be acted upon, [Satan’s way] save it be by the punishment of the law at the great and last day, according to the commandments which God hath given. [God’s judgment to those who choose Satan.]
27 Wherefore, men are free according to the flesh; and allthings [good and bad] are given them which are expedient unto man. And they are free to choose liberty and eternal life, through the great Mediator of all men, or to choose captivity and death, according to the captivity and power of the devil; for he seeketh that all men might be miserable [restricted] like unto himself. (2 Nephi 2:18-27)