After expelling Adam and Eve from the Garden of Eden, God posted angels with flaming swords near its perimeter to ensure they didn’t come back in. Ever wonder why?
The most obvious answer is as a consequence of their disobedience. God warned them what not to do; since they disobeyed, He had to impose consequences.
But an often-overlooked reason relates to what could still happen if humans got back in. The only limitation God put on the original pair was to avoid eating from the Tree of the Knowledge of Good and Evil. They obviously missed the mark there, but the Garden still had a very special tree whose fruit would catastrophically affect fallen humans: the Tree of Life.
“And the Lord God said, ‘The man has now become like one of us, knowing good and evil. He must not be allowed to reach out his hand and take also from the tree of life and eat, and live forever.’” – Genesis 3:22
Genesis isn’t terribly clear on whether they ate from the Tree of Life before they sinned, but it’s probably safe to assume they did at some point (how could you not try everything the Garden has to offer?). I can’t honestly say I understand what happens when sinless humans eat that tree’s fruit, but it would be a pretty big deal if an imperfect, sinful human ate from it. The verse above makes it pretty clear they’d be preserved in a sinful state forever. Christ still died for them/us, but without death, how can we ever be restored to true life?
In His infiniteness, God could doubtless still make a way to redeem them, but He chose, in His mercy, to prevent anyone from reaching the tree in the first place.
Still can’t get over the loss of that tree? Don’t worry, we’ll have access to it in the future: Revelation 22:1-3a notes “Then the angel showed me the river of the water of life, bright as crystal, flowing from the throne of God and of the Lamb through the middle of the street of the city; also, on either side of the river, the tree of life with its twelve kinds of fruit, yielding its fruit each month. The leaves of the tree were for the healing of the nations. No longer will there be anything accursed.” Don’t worry; you’ll get your shot at that tree (and its 12 different kinds of fruit) someday!