Merry Christmas! This is why we celebrate.

Therefore the Lord himself will give you a sign: The virgin will conceive and give birth to a son, and will call him Immanuel. (Isaiah 7:14)

For to us a child is born,
    to us a son is given,
    and the government will be on his shoulders.
And he will be called
    Wonderful Counselor, Mighty God,
    Everlasting Father, Prince of Peace.
Of the greatness of his government and peace
    there will be no end.
He will reign on David’s throne
    and over his kingdom,
establishing and upholding it
    with justice and righteousness
    from that time on and forever.
The zeal of the Lord Almighty
    will accomplish this. (Isaiah 9:6-7)

In those days Caesar Augustus issued a decree that a census should be taken of the entire Roman world. (This was the first census that took place while Quirinius was governor of Syria.) And everyone went to their own town to register. So Joseph also went up from the town of Nazareth in Galilee to Judea, to Bethlehem the town of David, because he belonged to the house and line of David.  He went there to register with Mary, who was pledged to be married to him and was expecting a child. While they were there, the time came for the baby to be born, and she gave birth to her firstborn, a son. She wrapped him in cloths and placed him in a manger, because there was no guest room available for them. (Luke 2:1-7)