Q: Would it really have been so terrible if Adam had eaten from the Tree of Life?
A: The Torah is the Tree of Life and eternal life for the soul. If Adam had eaten from the Tree of Life in the Garden of Eden, this would have brought his undeserving body eternal life. This would not have been good for Adam in his impure state after the sin. It would have eternalized, God forbid, the blemished state of sin, as Adam had not yet completely rectified what he was capable of rectifying. (Just think of what it would be like for someone to live eternally today – nothing could be more nightmarish).