How do we know that Christ must die for our sins?

The necessity of Christ's death is affirmed in various passages, highlighting that He must die to fulfill His role as our substitute and to execute God's covenant promises. Matthew 16:21 shows Jesus declaring to His disciples that He 'must go unto Jerusalem and suffer many things.' This 'must' signifies that His death was predestined as part of God's sovereign plan for redemption. Hebrews 2:14 emphasizes that Christ took on flesh and blood to destroy the power of death and to save His people from their sins. His sacrificial death fulfills the requirements of divine justice, allowing God to be both just and the justifier of the one who has faith in Jesus (Romans 3:26).