How do we know that Christ had to die for our sins?

The Scripture reveals that the death of Christ was not only a prophetic necessity but a fulfillment of God's justice. For example, Romans 8:3 states that God sent His Son in the likeness of sinful flesh to condemn sin in the flesh. This means that Christ's death was essential because it was the only way to satisfy God's holiness and righteousness. We cannot earn salvation through our deeds, because we are all sinners and unable to keep the law. Grace necessitates that someone take our place, which was realized in Christ’s obedience unto death. His death abolished the power of sin and provided a way for believers to be declared righteous before a holy God, fulfilling the demands of the law.