This is a question that has perplexed me for years. How could Adam and Eve be punished for eating of the fruit of the tree that contained the knowledge of good and evil? How could they have possibly known that obeying God was good and disobeying God was evil without eating the fruit? Is it possible that this story was not meant to be taken literally? Maybe it illustrates a much broader point?
Hi SPB, nice to speak with you again

Yes I can see your thoughts are healthy and you've raised a good question that many people just seem to doubt without really delving into it. Notice the quote in razeontherocks signature:
There is nothing in the Mosaic books that yields its meaning on the surface. No rabbi ever read Genesis literally until modern times! - Rabbi Jonathan Sacks
Don't get me wrong, I do believe that Genesis is a literal account of the origin of man, and I do believe that Jesus had that sort of faith too. But I also believe the story of Adam and Eve is meant to illustrate a much broader point while giving the literal answer to why the human is so corruptible.
To me the story illustrates the big problem we get when we choose not to obey what God tells us and instead choose to believe a lie. The serpent is illustrated as the tempter, and in so much as we can be tempted to disbelieve what God says, the tempter is the most cunning creature in the world. Jesus inflated this theme in
John 8:44 by saying that the devil is the father of lies and was a murderer since the beginning.
This thinking seems to loop upon your original question: is it meant to be taken literally. The answer to this, according to what the impact of not listening to God has, is a resounding yes. Either you will choose to listen to what God says or you will choose to argue about it, and this is why we see non-believers coming up to Christianity with all the arguments under the sun why it can't be true, and the Christians come back with all the verses in God's Word to state that it is true. It is the royal battle between truth and lie, light and dark. Ultimately the whole battle comes down to the one simple verse that convinced Pontious Pilate of Jesus' innocence:
John 18:37
New Living Translation (NLT)
37 Pilate said, So you are a king?
Jesus responded, You say I am a king. Actually, I was born and came into the world to testify to the truth. All who love the truth recognize that what I say is true.
We see many people arguing with the Genesis account, but more importantly, arguing with the account of Jesus and the commandments He gave. It takes a drastic change of heart for someone who doesn't believe what God says to suddenly turn about-face and begin believing everything that He says. It's a wonderful experience to be born again, and to realize that God doesn't lie. The moment that becomes real to you, your life will begin again.
Let me know how this fits with the way you think of it.