Why is Christ's death necessary for salvation?

The necessity of Christ's death for salvation is rooted in God's justice and holiness. As stated in John 16 and demonstrated throughout Matthew 27, Jesus' crucifixion was predetermined for the good of His elect, satisfying God's law and justice. His atoning sacrifice not only covers the sins of His people but also establishes the righteousness by which they are justified before God. This imputation of Christ's righteousness guarantees salvation to all who believe, affirming that without His death, no spiritual life could be given.