This unique tree is referenced in only three Bible books (Genesis, Proverbs and Revelation) for ten times total. Its first mention is in Genesis 2.
The tree of life also was in the middle of the garden, and the tree of the knowledge of good and evil (Genesis 2:9, HBFV throughout).
Eden's two choices, placed before Adam and Eve (Genesis 3), represented far more than simply deciding what to eat. They symbolized whether our first parents would trust their Creator and follow his definition of what was right and wrong, or decide for themselves what was or was not sin (influenced, of course, by the devil).
Our first parents, by eating the forbidden fruit, chose to rely solely upon themselves (their own reasoning, emotions, etc. apart from God), and Satan's subtle lies, to determine how they lived. The consequence of this action was to close off this unique tree from humans.
God, who wasn't surprised humans rejected him, decided to use their separation (Genesis 3:23) as a means to expose humanity to his adversary's crooked way of thinking. He would then, in his own time, open each person's eyes to the truth and give them a full chance to live forever.
Why Was It Protected?
Why did God have this tree protected by cherubim after Adam and Eve sinned? Why was a powerful angel, wielding a mighty flaming sword, needed to bar anyone from coming even near it (Genesis 3:23 - 24)? The implication of Genesis 3:22 is that eating of its fruit would have enabled Adam and Eve to live forever. Because, however, they had rejected God's way, such an existence would only have been filled with frustration, misery and pain.
What Happened to It?
What happened to this tree after the sin and banishment of our first parents? Although the Bible is silent on its fate, it was almost certainly destroyed during Noah's flood. The floodwaters, since they covered the entire world, would have eradicated any trace of the Garden of Eden and its plant life (Genesis 7:17 - 23).
Those called by God to repent can choose to begin living and thinking as he does. As a person begins to adopt more and more of his holy beliefs, it enables them to bless others by becoming an example of goodness.
The fruit of the righteous is a tree of life, and he who wins souls is wise (Proverbs 11:30, see also 3:18, 13:12 and 15:4).
Will It Come Back?
The last Biblical mention of this unique tree undeniably underscores its symbolism and the blessing it brings. Only those who make God the authority in their lives and obey him (keep his commandments) will earn the right to receive the gift of eternal life.
Blessed are those who keep His commandments, that they may have the right to eat of the tree of life, and may enter by the gates into the city (Revelation 22:14).