"Did Adam and Eve eat of the tree of life before they sinned? In Heaven you state that Adam and Eve ate of the tree of life. But in Genesis 3:22 Adam and Eve now know the difference between good and evil and God drives them out of the garden. They don't eat of the tree of life which would allow them to live forever in an unregenerate state. To prevent them from being able to access the tree of life, a cherubim is put at the entrance of the garden to prevent access. So no one yet has eaten from the tree of life."
In Gen. 2:9 God placed the tree of life and the tree of good and evil in the center of the garden. In Genesis 2:17 God told Adam “You are free to eat from any tree in the garden but you must not eat from the tree of the knowledge of good and evil.” God didn't say you may eat of any fruit except from the tree of good and evil and the tree of life. We can assume that the tree of life was included in that invitation to eat and Adam and Eve did eat from it, until they sinned and were removed from the garden.
(See chapter 25 of Heaven for further explanation of the tree of life)