God told the first man, Adam, that he and Eve could not eat the fruit of the tree of the knowledge of good and evil, or else they would die.

Adam and Eve chose instead to listen to Satan, the tempter. They disobeyed God’s specific command, so sin entered the world, and death with it (Rom 5:12).

Death and sin go hand in hand: the cause of death is sin (Rom 6:23). Sin separates us from God, who is holy. Apart from Him who is the source of life, we no longer have His eternal life in us. Our bodies are mortal, and our spirits, because of sin, are condemned to eternal death.