How do we know Jesus' death was necessary for salvation?

The necessity of Jesus' death is rooted in Scripture, and is poignantly expressed in John 11:49-50, where Caiaphas, though unwittingly, prophesied that it was better for one man to die for the people than for the whole nation to perish. This underscores the sacrificial nature of Jesus' mission, which fulfills both Old Testament prophecy and divine continuity in redemption. His death was essential, not only for the Jewish nation but for all of God's scattered children, establishing Him as the Lamb of God who takes away the sin of the world and solidifying the promise of salvation for believers throughout all time.