A really hard question on Satan and deception.

[Mister Agenda]

Surely you can't be serious, the only way you can read that into scripture is with blinders on.
NAS Gen.2:16-17 And the LORD God commanded the man, saying, "From any tree of the garden you may eat freely; but from the tree of the knowledge of good and evil you shall not eat from it, for in the day you eat from it you shall surely die.
Gen.3:2-3 And the woman said to the serpent, "From the fruit of the trees of the garden we may eat; but from the fruit of the tree which is in the middle of the garden, God has said, 'You shall not eat from it or touch it, lest you die.' "

Both these passages show that they had been told not to eat the fruit or they would die. They ate and lost their pure spiritual lives and they also had death come into their lives. This is why God would not allow them to eat from the tree of life, they would have had an eternal life that was sin filled and what a miserable life that would have been, God granted them His grace by not allowing them to eat of the tree of life. Actually this is the hell that nonbelievers will live, eternity in sin and misery. Eve demonstrates that they knew it was wrong to eat from the tree of good and evil. Adam and Eve died a spiritual death when they ate the fruit and then later in life would physically die. I do not know how many times scripture tells us that spiritual death is separation from God but it's many times, and because God can not be in the presence of sin, we've become separated from Him because of Adam and Eve's disobedience. This is simple why can you not understand it. This i the reason that Christ came and redeemed us through His death and resurrection.

Eve demonstrates that she knew she had been told she would die the day she ate the fruit. That doesn't demonstrate she understood right and wrong, only that she understood fear. Then, some snake tells her God lied about the dying thing and she, not knowing good from evil, bought the snake's story and tried the fruit, and lo, lived many years after.

You really should want this story to be a moral allegory about why we have destructive urges that we often give into when we know better. As a literal event (besides all the biological evidence against it), you're stuck with a God who does the moral equivalent of locking two children in with a psychopath and a shotgun and blaming the children when it goes south.

---

Why would God tell them that they would die if they ate from the tree if they were already going to die?

God told them they would die that day if they ate the fruit. They ate the fruit and did not die that day, but lived for centuries after, according to Genesis.

You're making up ad hoc explanations based on the assumption that what you read MUST be true and good. It works like this: I believe that everything Tim writes is good and true. Tim writes 'twinkies are good for you' on one page, and 'twinkies are bad for you' on another. Now I have a dilemma: either accept that Tim has contradicted himself, believe two contradictory things at once, or contrive a story that explains how what Tim wrote the first time was true and what he wrote the second time was also true. Clearly, the latter is how you read the Bible: you just make up a story (or buy into someone else's ad hoc explanation) that sounds like it would resolve a conflict and declare it must be true...because otherwise you would have to accept that the Bible is not inerrant or have your head asplode. The problem with ad hoc reasoning is you can make ANY statement true if you get to make up the context and determine the 'true' meaning.