The Tree of Life changes you.
When you eat of it you are changed.
The moment you eat of it your flesh goes from being naturally mortal, to everlasting.

Thats how we know God created humans as mortal creatures.
The tree of Life is the proof we find that Adam was created out of the dust as a mortal creature,

Humans were designed as mortal creatures that had the ability to eat of the Tree of Life and live forever.

That is why the Tree Of Life is so important in understanding the mortal state man was created in.
It was the act of eating from the tree of Life that was to keep Adam from death.

The moment God kicked man out of the garden and out of reach of the Tree, man was condemned.
The moment Adam was unable to eat, he was doomed.
And that is why Adam died just like any other animals in creation.

Adam was created as a mortal creature, and he died as a mortal creature