18 …he [Satan] said unto Eve, yea, even that old serpent, who is the devil, who is the father of all lies, wherefore he said: Partake of the forbidden fruit, and ye shall not die, but ye shall be as God, knowing good and evil.
21 And the days of the children of men were prolonged, according to the will of God….
22 And now, behold, if Adam had not transgressed he would not have fallen, but he would have remained in the garden of Eden. And all things which were created must have remained in the same state in which they were after they were created; and they must have remained forever, and had no end.
One of the great things about Lehi’s discourse on the Fall is that he gives us something that no other place in scripture gives us—Adam’s reasons for partaking the fruit. All other places say that “[Eve] took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat” making it sound like Adam ate mindlessly what Eve gave him.
But here we get the first inkling (though it is not explained fully) that Adam fell (ate the fruit) so that he could have children. This suggests something we are familiar with—that Adam and Eve knew they would have to separate if one ate the fruit and the other did not, that Eve would have to leave the Garden of Eden and Adam would not need to.
Think of what would have happened if Adam had decided not to partake of the fruit too. He and Eve would have been separated and would not have been able to have children. Not only that, Eve would have been endlessly lost, having fallen forever, and being separated from Adam, so she would have been unable to have children, especially the distant descendant Jesus Christ who would atone for her sins as well as all others.
The apostle Paul realized this too, since he wrote to Timothy:
14 And Adam was not deceived, but the woman being deceived was in the transgression.
Paul’s words about Adam not being deceived seem totally incomprehensible unless we take it as a hint that Adam was tempted to eat the fruit once before and resisted the temptation, and it was only the prospect of losing Eve and the means to have children that persuaded him to eat the fruit.
Paul’s words also highlight that Eve’s salvation (and everyone else’s too) depended on her having children. She had to have children, her children had to have children, and so on, to ultimately bring Christ into the world so He could atone for us.
LDS scholar Hugh Nibley pointed out that Eve, though fallen, still exhibited great love of the truth by working to keep her marriage together so that she could keep the commandment to have children. (Having broken one commandment, she didn’t want to break any others.)
After Eve had eaten the fruit and Satan had won his round, the two [Adam and Eve] were now drastically separated, for they were of different natures. But Eve, who in ancient lore is the one who outwits the serpent and trips him up with his own smartness, defeated this trick by a clever argument. First she asked Adam if he intended to keep all of God's commandments. Of course he did! All of them? Naturally! And what, pray, was the first and foremost of those commandments? Was it not to multiply and replenish the earth, the universal commandment given to all God's creatures? And how could they keep that commandment if they were separated? It had undeniable priority over the commandment not to eat the fruit. So Adam could only admit that she was right and go along: “I see that it must be so,” he said, but it was she who made him see it. This is much more than a smart way of winning her point, however. It is the clear declaration that man and woman were put on the earth to stay together and have a family—that is their first obligation and must supersede everything else.(Hugh Nibly, “Patriarchy and Matriarchy”, http://maxwellinstitute.byu.edu/publications/transcripts/?id=151)
So it seems that both Adam and Eve must be remembered for their strong commitment to marriage and family and having children.