Mentioned briefly only in Genesis 2:9, the Tree of Life is not given any attention in the scriptures until right before God banishes Adam and Eve from the garden. The existence of such a tree, “in the midst of the garden” (2:9), implies it was intended for Adam and Eve to eventually discover. Two things lead me to believe we were never created immortal, but that God still intended for us to be:
1) Since The Tree of Knowledge of Good and Evil was the only tree made off limits, the Tree of Life is rendered entirely approachable and discoverable in the Garden. God even says, “lest [man] reach out his hand and take also of the tree of life and eat…” 2) It is impossible to attain eternal life if one already has it. God establishes in the same sentence that if man does eat of this fruit he will “…live forever”. Either Adam and Eve did not discover the tree yet, and its effects would have been much like that of the forbidden tree with permanent change from one bite, or its fruit was simply a part of their daily food pyramid, which would reasonably explain why Adam and his successors lived for hundreds of years after being cut off from the supply, and also how their years began to dwindle over time; the eternal genes dissipating with each generational step. Whatever the case, man was at one point dependent upon the Tree of Life to live forever. Which, many years later, would be replaced by only one other tree, one which all would be allowed to taste and see its goodness and find, once again, eternal life.
It does not appear to me that God revoked access to this tree (3:23) because it would be bad for his creatures to eat of it along with the forbidden tree, but rather that this was an immediate consequence for the choices of Adam and Eve. When they chose the forbidden tree, they in turn declined the Tree of Life. When they disobeyed, they invoked God’s justice. Although it is not made entirely clear whether they knew of the Tree of Life at the present time, they knew full well what tree not to eat of.
I can only think of my own failures. There have been so many times in my life I have chased after what I can only see in front of me, or even what God has directed me away from, and I have missed blessings God would have otherwise preferred I had waited for or discovered. Yet, this is what makes His grace all the more magnificent; when I pursue the wrong things, yet am blessed anyway! The same grace our Father had shown to his first two children is the same grace He continually lends to us.
His patience and mercy will forever be unparalleled.