The Christmas story is one of good news and great joy, but it is also quite a short one. There are 27 books in the New Testament part of the bible, but the story is only told in the books written by Matthew and Luke, two of Jesus' followers and friends. In Matthew, the story is told in two out of the 28 chapters and in Luke, it is told in two chapters out of 24.
Both Matthew and Luke finish their telling of the story with Joseph, Mary and Jesus returning to Nazareth to live. But Christians believe that Christmas was only the beginning of the amazing life of Jesus.
To Christians, one of the most important things about Christmas is what 'Christmas' really means - the Mass of Christ (or Jesus). Mass (or Communion) is a Christian act of worship when Christians remember that Jesus was not only born, as told in the Christmas story, but that, when he became a man, Jesus willingly died to take away all of our wrongdoings and bring us closer to God. Then he came back to life three days later. Christians celebrate this throughout the year, but especially on Good Friday and Easter Sunday.
Nothing has ever been the same since the first Christmas and you can find out more about Jesus' life in the Bible.