Jesus Christ, the eternal Son of God, had to die because God's justice and truth demanded a perfect satisfaction for human sin that only the death of the God-man could provide. By His death, He paid the debt of death for His people, abolished the power of sin, and secured eternal life.
The necessity of Christ's death is rooted in the character of God. As the Heidelberg Catechism — Question 40 reminds us, the justice and truth of God required a full satisfaction for our sins, a debt that could be paid in no other way than by the death of the Son of God. On the Incarnation of the Word — Section 20 clarifies that because the debt of death was owed by all humanity, it was necessary for the Word to take on a body capable of death—a human body—so that He could offer it as a sacrifice in our stead. Through this, He made us free of our trespasses and destroyed the power of death.
Why would the Creator endure such suffering? It was not merely a mechanical transaction, but an act of infinite grace motivated by His love for His Father and for us, as noted in the Small Catechism — Question 9. Our Savior stepped into our history to liberate us from the very fear that haunted our existence. As the writer to the Hebrews declares: "Since then the children are sharers in flesh and blood, he also himself in like manner partook of the same; that through death he might bring to nought him that had the power of death, that is the devil; and might deliver all them who through fear of death were all their lifetime subject to bondage." (Hebrews 2:14-15).