It’s Easter, not Christmas that’s the heart of Christianity
You’ve only got to look at the four gospels to see that. Two of them, Mark and John, don’t talk about the “Christmas-event”, the birth of the Lord Jesus, at all. The other two gospel-writers, Matthew and Luke give quite a lot of space to the build-up months earlier, and the aftermath months later. But they actually give very little to the birth itself or the events around it. Matthew deals with them in one sentence: “When Jesus was born in Bethlehem of Judaea in the days of Herod the king…” while Luke gives them twenty verses (Luke 2:1-20).
Compare that with the account of Jesus’s death. Matthew takes eight of his 28 chapters to describe the “Easter week” – the week of Jesus’s death and resurrection. Mark takes six of his 16 chapters, Luke six out of 24, John no less than 9 out of his 21 chapters. Jesus lived on earth for around thirty-three years. But the gospel writers devote one in three of their pages to just eight days out of those thirty-three years: the eight days between Palm Sunday when Jesus rode into Jerusalem and Easter Sunday when he rose from the dead. For the gospel writers, the story of Jesus’s death and resurrection was by far the most important part of his story.