Celebrate because God can do anything.
In our first week, we start in Luke 1:5-25, 57-66, where we find Zechariah and Elizabeth. They were unable to have children. On top of that, they were older, and having a child of their own seemed impossible. Then one day, an angel came to Zechariah and told him that he would indeed have a son, and that son would prepare the way for the Promised One, Jesus. Zechariah and Elizabeth learned that anything is possible with God.
Celebrate because God can do anything. Much of what we celebrate at Christmas is an incredible reminder that God can be trusted no matter what. When all seems hopeless, God comes through. God makes what seems impossible possible. No matter what we face in life, we can find joy and celebrate that God is at work and can help us through our circumstances.