They had not.
(I shall chastise them with love, as the scriptures telleth us)
Which meant we needed to spend time looking at the events in Genesis, and then at the same events as recorded in the book of Moses. Moses holds the doctrine lost from Genesis.
We left off around Genesis 2, when Adam and Eve had just been physically created, and were placed in the Garden of Eden. Do you remember?
Before moving on, I want to recap a few points about the physical creation of man.
(Someone in my class asked about Eve being created out of the rib of Adam ...)
Have a look at Genesis 2:18. As indicated by footnote 18b, the Hebrew term for the phrase "help meet for him" literally means 'a helper suited to, worthy of, or corresponding to him'. The King James translators at the time rendered the phrase 'help meet' because the word meet in sixteenth century English meant 'fitting' or 'proper'.
But language changed. And other silly translators came along. In the seventeenth century, the two words help and meet were mistaken for one word. So 'helpmeet' came to me 'a wife'. THEN, in the eighteenth century, in a misguided attempt to make sense of this scripture, the spelling 'helpmate' came about. The original meaning of the phrase had been obscured.
Why do I tell you this? I want to understand the relationship God intended for Adam and Eve better.
President Spencer W. Kimball taught that the term man in the story of the creation refers to "a complete man, which is husband and wife".  I should hope so! He also taught that the detailed description of the creation of Adam and Eve describes their relationship (i.e. help meet) as "corresponding to each other", and prescribes the ideal of unity between a man and a woman. The significance of the phrase "help meet" is that the woman is a creation who is a fitting and proper companion for Adam, because she is like him and corresponds to him.
I like that.
That concept is further solidified by the description of the creation of woman as being formed from the rib of Adam - a rib being a metaphor for a person corresponding to Adam. It is to be taken figuratively. 
"I presume another bone could have been used, but the rib, coming as it does from the side, seems to denote partnership. The rib signifies neither domination nor subservience, but a lateral relationship as partners, to work and to live, side by side." This proper role of the man and woman is clarified in the scriptural injunction that they should leave their parents and cleave unto each other, and become one flesh.
Talking about flesh, read Genesis 2:7. Note the word 'flesh'. It means mortality.
Last week, we discussed the spirit creation of man - that all things were created spiritually long before they were created physically. Which means they could not die.
When Adam and Eve 'fell', a change took place (it's described here in Moses chapter 4), and all things became natural, meaning they were now subject to death. So Adam and Eve had natural physical bodies (go and read 2 Nephi 2:22). If I were you, I'd mark the difference between spiritual and natural in your scriptures. Or at least note their meanings.
(None in my class marked them ... do people still mark their scriptures these days?)
Here is a diagram of the difference stages in Adam's existence (as described in Genesis 2 and Moses 3):
(source: Old Testament Seminary Student Manual)
Now let us look at how that Fall happened.
Remember, the world only has the Genesis account, which doesn't discuss any doctrine at all.
Also remember, the overall purpose of the events in Genesis 3 is this, as taught by Lehi:
"Adam fell that men might be; and men are, that they might have joy." (2 Nephi 2:25, bold obviously added)Before reading about the fall, consider these basic principles:
- When Adam and Eve were placed in garden, they were not subject to the power of death. They could have lived there forever, in a state of innocence, forever. And if that happened, the earth would have remained in that same state forever too. And everything on the earth. In a type of limbo, if you like.
- In that situation, there would have been no children. No making babies. No experiencing joy, sadness, labour pains, tough decisions, none of that stuff. Hence the limbo.
- By eating the forbidden fruit (and violating the law under which Adam was placed), their nature was changed. It all changed. Man became subject to (1) spiritual death, which is banishment from the presence of God; and (2) temporal death, which is separation of spirit and body.
- So .. this transgression brought about mortality, and the children of Adam and Eve inherited mortal bodies and became subject to the mortal death.
- And .. obviously the state of the earth and everything on it changed to suit the mortal condition of man. Everything became subject to mortality, even the earth.
- The is the best bit : to defeat the power which death had gained, it became necessary that an infinite atonement be offered to pay the debt. It was necessary; it would restore Adam and Eve and all their posterity - in fact all things - to immortal life through the resurrection.
With these principles in mind, we now need to read Genesis 3:1-6 (and/or Moses 4:5-12):
Now the serpent was more subtil than any beast of the field which the Lord God had made. And he said unto the woman, Yea, hath God said, Ye shall not eat of every tree of the garden?
And the woman said unto the serpent, We may eat of the fruit of the trees of the garden:
But of the fruit of the tree which is in the midst of the garden, God hath said, Ye shall not eat of it, neither shall ye touch it, lest ye die.
And the serpent said unto the woman, Ye shall not surely die:
For God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be as gods, knowing good and evil.
And when the woman saw that the tree was good for food, and that it was pleasant to the eyes, and a tree to be desired to make one wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat.
So "... the forbidden fruit had the power to create blood and change his nature, and mortality took the place of immortality."  Woah.
Here's an interesting side note for ya: Who did Satan tempt?
According to Genesis and Moses, he only approached Eve. But he actually approached Satan first. There are other scriptures that confirm this, as well as latter-day revelation. Have a look, you'll find it's in there ...
Now let's talk about the agency that the Lord gave Adam and Eve.
Agency is the ability to make choices and be accountable for them. It's absolutely necessary for everyone who desires to become like God. Which means Adam and Eve needed to exercise their agency and partake of the tree of knowledge of good and evil, so they could progress to become like Heavenly Father.
PLUS, eating that fruit made it possible for the rest of Heavenly Father's children to come to earth and exercise their own agency. Yay for fruit!
For agency to exist, four principles must be in operation:
- You must have a choice.
- You must know the alternatives.
- You must have an indication of divine will.
- You must have absolute freedom to choose.
So were all four principles operating for Adam and Eve?
But of the tree of the knowledge of good and evil, thou shalt not eat of it, nevertheless, thou mayest choose for thyself, for it is given unto thee; but, remember that I forbid it, for in the day thou eatest thereof thou shalt surely die. (Moses 3:17)
What do you think?
 Ensign, Mar. 1976, p.71
 Spencer W. Kimball, ibid
 Russell M. Nelson, "Lessons from Eve", Ensign, Nov. 1987
 Doctrines of Salvation, 1:76-77