Prior to the fall, Adam and Eve identified with God who was their father. Their father was Spirit (John 4:24) so they saw themselves as spirits clothed in flesh. They were given bodies to interact with creation. Their Father provided an environment that was perfectly compatible with them: all of their needs, their safety, their well-being, etc., the environment accommodated all their concerns.
They would gain wisdom and understanding by putting into practice what their Father showed them. By this lifestyle, following the direction of their Father in all they did, they would come to understand both good and evil.
"But solid food belongs to those who are of full age, that is, those who by reason of use have their senses exercised to discern both good and evil."
We might think, "But, without sin, why is knowing good or evil important?" Part of the destiny of man is to judge angels. Even if Adm and Eve continued without sin, they would have to know the basis upon which to judge the angels who rebelled.
The difference was HOW the knowledge of good and evil was obtained. There was nothing special about the fruit of the tree. It was not magic. It was simply off-limits for their direct consumption. Man was never to be the arbiter of good and evil. He was always supposed to gain such wisdom from his Father, God, and walk in His ways which are always righteous and good.
As they consumed the fruit they immediately identified with their physical make-up and saw themselves as flesh and, therefore, naked: previously
they saw themselves as spirits clothed in flesh.
As an aside, this is why, in the ministry of reconciliation,
we are to regard "no man after the flesh".
"There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus."
To continue: when it reads
"and their eyes were opened" this is not a reference to their physical eyes.
This is a reference to the eyes of their soul. They saw how the fruit could benefit them even though consuming it was contrary to the way of their Father.
And this is the crux of the issue: original sin. This sin is summarized in the scripture thus:
"For all that is in the world—the lust of the flesh, the lust of the eyes, and the pride of life—is not of the Father but is of the world."
Jesus tells us such lusts and pride are
the ways of the world. It's no mystery, then, that as the world proceeds to its end, lawlessness will abound. Lawlessness is when people do what is right in their own eyes.
So, the world of man-kind is approaching a dichotomy: there will only be two sons left in the world. The side that has rejected God will do what is right in their own eyes: they will make up rules and laws that serve their own purposes. This "son" is called Adam. He will be completely lawless, consumed with his own lusts and desires. The other side, reconciled to God's original intent through Christ, will live by the Spirit, only doing what they see their Father doing. This son is "Christ". all who believe on Him for life will be included in Him.
I'll stop here. As I began writing I envisioned only a couple paragraphs.
Blessings