Genesis 2:9 tells us, “out of the ground Jehovah God caused to grow every tree that is pleasant to the sight and good for food, as well as the tree of life in the middle of the garden and the tree of the knowledge of good and evil.” In verses 16-17 we read “Jehovah God commanded the man, saying, Of every tree of the garden you may eat freely, but of the tree of the knowledge of good and evil, of it you shall not eat; for in the day that you eat of it you shall surely die.”
Adam and Eve did eat of that tree but it may seem that they did not die that day. Was God’s word wrong? Certainly not. On the day they ate, they did not die physically. But they died spiritually. They were separated from fellowship with God and hid themselves from God (3:8).
Four thousand years later God came in Christ to be a God-man, live a perfect human life, die to redeem us from sin and death, and resurrect to regenerate us. In resurrection, God in Christ is life to us, the life symbolized by the tree of life in the garden. “Our Savior Christ Jesus nullified death and brought life and incorruption to light” (2 Tim. 1:10).
Today the tree of knowledge, the tree of separation from God, still has an influence. But in New Jerusalem, there is only one tree, the tree of life (Rev. 22:2). The other tree, the tree of knowledge, has been removed; it is something of death and all death is in the lake of fire. In New Jerusalem we will be eternally in life and in fellowship with God.