“Then the Lord God said, “Behold, the man has become like one of us in knowing good and evil. Now, lest he reach out his hand and take also of the tree of life and eat, and live forever—” therefore the Lord God sent him out from the garden of Eden to work the ground from which he was taken.He drove out the man, and at the east of the garden of Eden he placed the cherubim and a flaming sword that turned every way to guard the way to the tree of life.” Genesis 3:22-24 (ESV)
It may seem cruel for God to kick man out of the Garden of Eden, but it was actually very loving! Had they stayed and eaten of the Tree of Life, man would have lived forever in sin and death. God removed man from the garden so he could save him.
Right there in the Garden of Eden, God promised to send someone who would crush Satan’s head while Satan bruised His heal.
“he shall bruise your head, and you shall bruise his heel.” Genesis 3:15 (ESV)
That someone–Jesus Christ–came. He died on a cross, with his heels bruised. And all who repent and believe upon Him will be saved and able to one day eat of the Tree of Life in a perfect world.
“And he shewed me a pure river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb.In the midst of the street of it, and on either side of the river, was there the tree of life, which bare twelve manner of fruits, and yielded her fruit every month: and the leaves of the tree were for the healing of the nations.And there shall be no more curse: but the throne of God and of the Lamb shall be in it; and his servants shall serve him:” Revelation 22:1-3 (KJV)
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. John 3:16 (KJV)