This meant, before they were cast out for sin, if they refused to eat the tree of life, they would grow old and die.

The tree represented immortality, not just living forever.
One can live forever and not be immortal, consider the devil, he is mortal and he had lived for ages as a loyal angel, and had the prospect of continuing... now soon he will die...

The tree represented God’s guarantee of life.

Genesis 3:22 shows us this, and that is why God had it guarded after he pronounced the sentence of death on Adam and Eve...

Had Adam and Eve been allowed to eat from that tree, it would have proved God a liar. (Genesis 2:17; 3:2-4) Because God commanded that they not eat from the tree of knowledge of Good and Bad or they would die. Satan is the one who said they would not die. If they ate from the tree of life after they ate from the tree of Good and Bad, Satan would have been telling the truth and God would have been a liar.

Eating of the tree of life means you have God's Guarantee You will never die, Forever.

Journey Well...

A little backward there.

They could eat anytime from the tree of life. They were thrown out after their sin so they would not eat of the tree of life. Angels and a flaming sword were placed at the entrance so Adam & Eve could not sneek in and eat of that tree.

It's an allegory about the mind. The tree of knowledge is the imperfect state of the Tree of knowledge, but experiential knowledge is through the division that the tree of knowledge invokes in dualism of mind so each aspect of mind can be developed and refine without deficiency. If there wasn't a deficiency before then it would've never been a need to eat of that tree, nor would a tree of life exist. Tree of knowledge of Good and Evil which is duality of mind/division is necessary to be eaten upon in order to get to the Tree of Life, its ultimate completion is when it embodies perfection and becomes the Tree of Life which grants that one becomes a God, or rather come to "Know Thy Self", that "Ye Are Gods" and know your Authentic Self which is a Being of radiant Light, and is all MIND.

Think about, what great deficiency they were in not knowing anything? The Tree of knowledge, or the enlightenment of the condition of the mind, as it dwelt within the polarities of male/female perceived through the allegory of Adam/Eve whole at once were of one body, but divided. What brought death was this division, but not a literal death but death in the manner of duality of mind. The female representing the principle of the reflective, being the Life which in grows the essence of the male. The male and female, the active and reflective brings forth the fruits of the tree of life, these polarities of mind have to engage within their own nature and as these facilities expand and interact to become a unified whole, there is harmonious in balance in the image of Life. Nor was the snake ever, it was and is an image of wisdom, its that quality of mind which leads one to recognize their deficiency/defective nature and thereby in mind can bring about resolution and become a fullness.

>> If God created humans to live forever in the garden of eden,
>> why a tree of life?

********I do not believe that humanity was created immortal. Apparently, even the angels are not immortal -- but God only.

1Tim. 6:13 I give thee charge in the sight of God, who quickeneth all things, and before Christ Jesus, who before Pontius Pilate witnessed a good confession;
1Tim. 6:14 That thou keep this commandment without spot, unrebukable, until the appearing of our Lord Jesus Christ:
1Tim. 6:15 Which in his times he shall show, who is the blessed and only Potentate, the King of kings, and Lord of lords;
1Tim. 6:16 Who only hath immortality, dwelling in the light which no man can approach unto; whom no man hath seen, nor can see: to whom be honor and power everlasting. Amen.

God bless.