This question came up after reviewing a chapter in Volume 2 of “Let’s Get Biblical” by Rabbi Tovia Singer: If the messengers don’t have free will, and Gen 3:22 refers to Gd’s heavenly court, how come they know the difference between good and evil? Then the L-rd G-d said: “Behold, the man has become like one of Us, to know good and evil.”
When Adam and his wife ate from the Tree of Knowledge, it became impossible for them to remain in the Garden of Eden. They were now fully imbued with principled understanding, possessed full moral knowledge of good and evil, and craved pleasure. Animals do not possess moral awareness. God is omnipotent and omniscient. He created everything, including evil, with no limitation. Moreover, He possesses unlimited knowledge and understanding.
Do angels possess the knowledge of good and evil? As it turns out they do, and one angel was tasked to seduce man into sin. Angels possess the knowledge that man only acquired following the sin in the Garden. Angels do not act upon this knowledge because they do not have free will; they have no independent agency. Angels are, however, supernal beings. They are not subject of the material limitations of death. Moreover, angels have no carnal needs; they do not crave physical pleasure. It is in this sphere that man stands alone as a unique being in the universe. Unlike animals, he fully apprehends the difference between good and evil. On the other hand, like animals, man craves physical pleasure.
If our first parents ate from the Tree of Life, what would have become of them? Man would have “become like one of us,” with one critical distinction: unlike angels, we would crave and pursue physical pleasure and never reach the spiritual heights for which we were created. In essence, if we were not banished from the Garden of Eden, the result would have been an epic disaster.