Genesis opens the Bible with two prominent trees: the Tree of Life and the Tree of the Knowledge of Good and Evil. The first allowed continued existence and the second an opportunity to exercise free will in rebellion against God. Adam and Eve ate of the second tree and lost access to the first. They came to know good and evil and also came to know separation from a unique fellowship with God and the pain of death.
Revelation closes the Bible with access to the Tree of Life restored, its life giving fruit, and a unique fellowship between God and man .
What connects these scenes of rebellion and peace, restraint and restoration? The cross of Jesus where the Savior was hanged upon a tree, cursed to redeem us from a curse (Galatians 3:13).
The cross became a Tree of Knowledge of Good and Evil for it informs us of the great evil that could crucify the Son of God, the exceedingly high price of sin, and the cost to redeem man. We also are taught of the exceeding love, mercy, and goodness of God who would make such a sacrifice to redeem us (1 John 5:20). We come to know God in a special way through the cross.
The cross is also a Tree of Life through which the death of Jesus brought righteousness and life (Romans 5). The cross lifted Jesus so that even those who look to Him today can find salvation and eternal life (John 3:14-15).