PRES. EZRA TAFT BENSON:
"Just as a man does not really desire food until he is hungry, so he does not desire the salvation of Christ until he knows why he needs Christ.
"No one adequately and properly knows why he needs Christ until he understands and accepts the doctrine of the Fall and its effect upon all mankind. And no other book in the world explains this vital doctrine nearly as well as the Book of Mormon" (in Conference Report, Apr. 1987, 106; or Ensign, May 1987, 85 ).
Some of the Book of Mormon scriptures that teach about the fall:
12 And it came to pass that when Aaron saw that the king would believe his words, he began from the creation of Adam, reading the scriptures unto the king—how God created man after his own image, and that God gave him commandments, and that because of transgression, man had fallen.
13 And Aaron did expound unto him the scriptures from the creation of Adam, laying the fall of man before him, and their carnal state and also the plan of redemption, which was prepared from the foundation of the world, through Christ, for all whosoever would believe on his name.
14 And since man had fallen he could not merit anything of himself; but the sufferings and death of Christ atone for their sins, through faith and repentance, and so forth; and that he breaketh the bands of death, that the grave shall have no victory, and that the sting of death should be swallowed up in the hopes of glory; and Aaron did expound all these things unto the king.
19 For the natural man is an enemy to God, and has been from the fall of Adam, and will be, forever and ever, unless he yields to the enticings of the Holy Spirit, and putteth off the natural man and becometh a saint through the atonement of Christ the Lord, and becometh as a child, submissive, meek, humble, patient, full of love, willing to submit to all things which the Lord seeth fit to inflict upon him, even as a child doth submit to his father.
2 Nephi 2:25
Adam fell that men might be; and men are, that they might have joy.