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

The Bible confirms the necessity of Jesus' death for salvation through various passages. In 1 Peter 1:18-19, we learn that believers are redeemed with the precious blood of Christ, which emphasizes the sacrificial nature of His death. It was through His being 'made a curse for us' (Galatians 3:13) that we could be released from the curse of the law. The atonement is central to the Christian faith, as it reflects God's justice and mercy simultaneously; sin must be dealt with justly, and Christ's death provides the means by which grace is freely extended to those whom God has chosen.