Plant in the garden of Eden symbolizing access to eternal life. Also, a metaphor used in Proverbs. For the biblical writer the tree of life was an important consideration only after Adam and Eve disobeyed. Sin interrupted the quality of life God intended for them. They were to obey God (Gen 2:17) in a family setting (Gen 2:18-25) and perform their
assigned tasks (Gen 2:15). The implication is that they had access to all the trees in the garden, including the tree of life, but God gave an explicit command not to eat of the tree of knowledge. Their relationship to God changed radically when they disobeyed that command. Chief among the radical changes was that they no longer had access to the tree of life (Gen 3:22-24).
The “tree of life” appears in Proverbs four times (Prov 3:18; 11:30; 13:12; 15:4) and in Rev 2:7; 22:2,14. To lay hold of wisdom is to lay hold on “a tree of life” (Prov 3:18). “The fruit of the righteous is a tree of life” (11:30). Yet another proverb has this comparison: “Fulfilled desire is a tree of life” (13:12 HCSB). The author of author proverb wrote, “The tongue that heals is a tree of life” (11:4). None of these proverbs seems to refer to “the tree of life” mentioned in Genesis. All of the references in Revelation do.