The short answer to why Jesus needed to die is that he needed to die so that we could be saved from death. The doctrine of salvation is referred to as soteriology, and there have been entire books written on the subject. So in the little space I have, I will attempt to explain the Catholic perspective on redemption.
In the Incarnation, Jesus, the Son of God, became human. In taking on human nature, Jesus began the process of reconciling humanity with God. Adam and Eve rejected God’s will in favor of their own. Because of their sin, we needed a savior. And Jesus — unlike Adam and Eve — lived his entire life in obedience to his Heavenly Father.
In his suffering and death on the cross, Jesus showed his total obedience to God the Father, thereby making up for our sins and gaining for us the gift of grace. Through his suffering and death we have been freed from slavery to sin and death, and by his resurrection we have been given the gift of eternal life. Jesus needed to die for us in order to restore humanity, so that we can be as God intended us to be. We still need to choose life over death by choosing the things of God over the things of this world, but through Jesus’ passion, death and resurrection, we have been given the grace to be able to do so.
Bryan Lowe, Sacred Heart of Jesus Catholic Church, Anniston
Sin perverted the living expression of God on earth
The Bible declares that God is love (1 John 4:8). God loved humans so much that he gave his only begotten Son, the eternal Word of God, who came to earth in the body of a man named Jesus. Jesus came to seek and to save “that” which was lost, and that which was lost was the very image and likeness of God, or love, that he used to create man. It’s hard for us to really understand why Jesus had to die because the world that we live in has been confused since man sinned and rebelled against God. The human family was created to be a living expression of God’s love, power and authority on the earth, but all of these were perverted by sin. Men and women are at odds with one another because of sin. The man seeks to rule over the woman, and the woman is not having any part of it. Jesus must die to redeem God’s order: God is the head of everything, man is the head of woman, Christ is the head of man and God is the head of Christ.
Man was created to glorify God. God warned man that if he ate from the forbidden tree he would die (spiritually). Spiritual death is separation from God. God cannot lie, so his word cannot be reversed. Because of Adam’s sin, all men are born in sin. God must fulfill the promises he made to man when he created him, so now God must provide the sacrifice to redeem man from sin. God’s delegated representative in the earth has sinned, so God has to now come into the earth through a human or earthen vessel, but the vessel must not be born through Adam. The Virgin Mary supernaturally conceives the seed of God, Jesus Christ, who declares, “If I be lifted up from the earth, I will draw all men unto me” (John 12:32). Jesus needs to die because only his death will make God happy — “It pleased the Father to bruise him” (Isaiah 53:10).
Bob McClain, Living By Faith Ministry, Oxford