God took on human flesh in order to be able to die. He did this so that such a death would be followed by a resurrection in which the identity of Christ would be proclaimed by God to the world. And this is the meaning of Christmas. This is why we celebrate Christmas. When Mary held the Desire of Nations in her arms, she was holding the body that would be broken and would be sacrificed for the life of the world.
Listen to the full sermon in this app, 'Fully God & Fully Man.'