The birth of Jesus would have been worth nothing to the human race without his death. It was the death of the Son of God that took away our sin, and therefore took away God’s wrath and the expectation of eternity in hell.
“You see, at just the right time, when we were still powerless, Christ died for the ungodly. Very rarely will anyone die for a righteous person, though for a good person someone might possibly dare to die. But God demonstrates his own love for us in this: While we were still sinners, Christ died for us.
“Since we have now been justified by his blood, how much more shall we be saved from God’s wrath through him! For if, while we were God’s enemies, we were reconciled to him through the death of his Son, how much more, having been reconciled, shall we be saved through his life!” (Romans 5:6-10)
There is nothing of merit in any human being, in God’s sight, that would make him want to do anything for us. Human beings by nature rebel against God. Paul has spent a few chapters before these verses showing that no human being is righteous, no one is good. And yet while we were still sinners, Christ died for us. And that is a measure of God’s love. As it says in John’s gospel, “For God so loved the world that he gave his one and only Son, that whoever believes in him might not perish, but have eternal life.” (John 3:16)
Jesus’ death did something for us, his people, through faith. It justified us. That means that in the sight of God, as eternal judge, under his law, we are no longer seen as sinners, no longer deserving his wrath and judgment. Sin has been punished – in God’s Son on the cross.
Paul, in Romans 5:6-10, describes it in two steps: We are justified through Christ’s death, so we will also be saved from God’s wrath. We were reconciled while we were still enemies, through the sole action of God in sending Jesus to die for us, so we will also be saved through his resurrected life.
Isaiah foretold this aspect too – “We all, like sheep, have gone astray, each of us has turned to our own way; and the Lord has laid on him the iniquity of us all.” (Isaiah 53:6)
Jesus, the Son of God, was born as a human being, with the intention of dying on a cross to remove the judgment upon our sin.