This is a great question! I love it! I don't know if this will satisfy your intellect, but it is the best explanation I've come across. The following is an excerpt from Dr. Hahn's book, "First Comes Love" and he tackles the issue of what was actually going on in the Garden of Eden at the time of the temptation by the serpent.
"Before we can understand Adam's sin, we must try to hear God's commandment as Adam would have heard it:
And the Lord God planted a garden in Eden, in the east; and there He put the man whom He had formed. And out of the ground the Lord God made to grow every tree that is pleasant to the sight and good for food, the tree of life also in the midst of the garden, and the tree of the knowledge of good and evil.... The Lord God took the man and put him in the garden of Eden to till it and keep it. And the Lord God commanded the man, saying, "You may freely eat of every tree of the garden; but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall die." (Gn 2:8-9, 15-17)
There are many oddities in this passage. They are not so odd for us, perhaps, living as we are in the world of darkness and shadows, but they certainly should seem odd to a man living in a perfect world.
In the preceding chapter, we discussed God's command to till and keep the garden. To till the garden seems reasonable enough. But remember that the Hebrew word translated as "to keep" means, literally, "to guard," as the Israelite priests guarded the sanctuary and kept it from defilement. Why should Adam have to guard paradise? God's command implied that there was something that must be kept out, something that might try to get in.
A second oddity appears in God's threat of punishment: "in the day that you eat of it you shall die." In some translations, the last phrase appears as "you shall most surely die." The Hebrew idiom is difficult to render in English. Translated verbatim, the text reads, "you shall die die." or "you shall die the death." It's a strange construction, the repetition of the word "die" or "death." The Hebrew language uses repetition -- as English uses the -est suffix in, for example, "greatest" or "weakest" -- to indicate a superlative. (When God says that He found creation "very good," the Hebrew actually reads, "good good.") The words "die" and "death," however, rarely appear in the superlative. After all, Adam couldn't get any deader than dead, could he?
Well, maybe he could. The ancient rabbis taught that this passage of Genesis implied that there are two kinds of death. “The death of the man is the separation of the soul from the body,” wrote Philo of Alexandria, a Jewish contemporary of Jesus. “But the death of the soul is the decay of virtue and the bringing in of wickedness. It is for this reason that God says not only ‘die’ but ‘die the death,’ indicating not the death common to us all, but that special death, which is that of the soul becoming entombed in passions and wickedness of all kinds. And this death is practically the antithesis of the death which awaits us all.”
The terms seem very clear now and even absurdly simple. If Adam kept God’s one small commandment, he would live his blissful life forever. If he didn’t, he would die the most extreme sort of death. It’s fair, though, for us to ask whether Adam could have understood the consequences of sin. What could death mean to a man who was preternaturally immune to death? For that matter, why did God plant the tree of life in the garden? Could such threats and such elixirs hold any meaning to an immortal man?
Yes, they could, and they did. Though God had made man preternaturally immortal, He had also made Adam’s body, which was mortal by nature, with a healthy, instinctive abhorrence of physical death. Otherwise, His threatened punishment – “the day that you eat of it you shall die” – would make no sense.
Now that we’ve examined that terms of God’s command, let’s give the serpent his due, looking over the fine print of his proposition:
Now the serpent was more subtle than any other wild creature that the Lord God had made. He said to the woman, “Did God say, ‘You shall not eat of any tree of the garden’?” And the woman said to the serpent, “We may eat of the fruit of the trees of the garden; but God said, ‘You shall not eat of the fruit of the tree which is in the midst of the garden, neither shall you touch it, lest you die.’” But the serpent said to the woman, “You will not die. For God knows that when you eat of it your eyes will be opened, and you will be like God, knowing good and evil.” So when the woman saw that the tree was good for food, and that it was a delight to the eyes, and that the tree was to be desired to make one wise, she took of its fruit and ate; and she also gave some to her husband, and he ate. Then the eyes of both were opened, and they knew that they were naked; and they sewed fig leaves together and made themselves aprons. (Gn 3:1-7)
Once again, in the original Hebrew we encounter many curious details that get lost in the translation. First, we may note that the serpent addresses not just Eve but Adam as well. He uses second-person-plural verbs, a construction we lack in English (except in Southern dialects in the United States, which use “y’all” for the plural form). For most English speakers, the word “you” means the person or persons who are being addressed. But Hebrew, like most other languages, makes a distinction between singular you and plural you.
The serpent speaks not to one person, but to the couple – yet who responds? Only Eve.
Where, then, is the man whom God commanded to guard the garden? He’s there. The serpent addresses him, but Adam is silent. He allows his wife to take up the serpent’s challenge; he allows her to continue the discussion… and he allows her to succumb to the serpent’s proposal. Why?
To understand this, we have to return again to the beginning of the narrative, to the time when God made Adam. Adam lived then in the presence of God as a son of God. Yet this aloneness was not good. God created Eve to be Adam’s companion and to make the divine image more perfect in humankind. But I believe that, even then, the work of man’s creation was not complete. God left something of the divine image for man and woman to bring to completion. God wanted man and woman in the human family, to imitate the communion, the covenant, that is at the heart of the divine family, the Trinity.
This is why God permitted Adam and Eve to undergo the ordeal with the serpent – which was surely an imposing and deadly beast. Elsewhere in the Old Testament, the Hebrew word here translated as “serpent,” nahash, denotes a dragon (see Is 27:1) or a sea monster (Jb 26:13).
What is clear is that Adam faced a life-threatening force, deadly in its intent and formidable in its subtlety. Moreover, the serpent seized on the one thing that humans had been created to dread instinctively: dying. The Catechism of the Catholic Church identifies the serpent as Satan (see no. 391) and spells out the power he had to seduce Adam, but also to harm him physically and spiritually (nos. 395 and 394).
All these circumstances pack power into the serpent’s words. In contradicting God’s command, the serpent said, “You shall not die.” Quoting the Lord God almost verbatim, the serpent introduced a deliberate note of ambiguity. In doing so, he subtly forced Adam to choose which death he wanted most to avoid: spiritual death or physical death.
Moreover, the serpent uttered an open-ended statement, leaving his thought unfinished, and leaving Adam and Eve to fill in the blank. “You will not die…,” the serpent said. The couple would not die, he implied, if they ate the fruit. The flip side, then, can be read as a threat: They would die if they refused to eat the fruit. They would die physically, and he would make sure of it.
Now, if the serpent was indeed a monstrous beast, and if Adam did indeed dread death, then suddenly we can understand our forefather’s silence. He feared his own death. Moreover, he feared his physical death more than he feared offending God by sin. He stood by quietly while Eve continued in conversation with the beast. He stood in silence while the serpent issued his veiled threat. The serpent addressed Adam, but the man never responded. Nor did he call out to God for help. In pride and in fear, he kept silent. And, with his wife, he disobeyed the command of the Lord.
What we have here is far more than a failure of nerve or breakdown in communications. It’s a failure of faith, hope, and love. Adam’s fears kept him from his duty to guard the garden. They kept him from trusting in his Father God, and they threw him back, in pride, upon the flesh of his flesh, bone of his bone.
Knowing the serpent’s power, Adam was unwilling to lay down his own life – for the sake of his love of God, or to save the life of his beloved. That refusal to sacrifice was Adam’s original sin. He committed it even before he had tasted the fruit, even before Eve had tasted the fruit.” (pgs. 64 – 70)
I hope this answers the question.
God bless.