The Tree of the Knowledge of Good and Evil is a prime example of physical reality highlighting spiritual truth (see John 3:12).
To begin with, God placed the tree in the middle of Paradise as a test; Satan perverted it as a temptation. In eating from the tree about which God said, “When you eat of it you will surely die,” Adam challenged God as arbiter of good and evil (Genesis 2:17).
Furthermore, the Tree of the Knowledge of Good and Evil is the symbol of choice—between obedience and disobedience, between majestic revelation (God’s truth) and moral relativism (my truth).
Finally, though Adam sinned, God responded with mercy. He drove Adam from the garden so that he no longer had access to the Tree of Life. To do otherwise would have doomed humanity to an endless physical existence in a fallen spiritual condition—which is precisely what hell is. Hell, however, can be averted. And Paradise regained.
As Adam’s descendants we can yet embrace the Tree of Life where the personification of all that is good paid the ultimate price to take all that is evil upon himself.