Question: If death is the consequence of sin then, by implication, had there been no sin, there would be no death. Why then would God have been concerned about Adam and Eve getting to the fruit of the tree of life? Apparently, prior to sin they would not have died. Why then is there a tree of life in the first place? (Genesis 3:17-22)
Answer: There is too much that we don’t know about the tree of life to give much of a definitive answer. It is possible that eating from the tree of life was a continual need for Adam and Eve in order to maintain their strength and health, since, even though there was not death, the body did need continued sustenance. But, if bodily death could not occur then what would be the point of eating, sleeping, or even protecting yourself from a tree falling on you or other natural dangers? It makes more sense to me that the absence of sin did not mean there was no death, but meant that death was not the normal occurrence from aging, and was not a punishment for disobedience. But it is likely death could happen if you failed to nourish the body or got injured.
The other factor that would limit death in an unfallen world would be the absence of malice in the human heart. But it might be possible to accidently kill someone. When sin entered, however, death began to reign in every person born because it was a punishment for Adam’s disobedience. Every human being was destined to grow old (a chemical process in which our cells cease functioning the way they’re supposed to) and, of course, death could be made even more abrupt and at younger ages because of the evil of the human heart. The tree of life might have been a factor in keeping our cellular structure from aging, and removal of access to this tree may have been the way God introduced the aging process into the fallen human race. Just a thought.