The wonderful thing about being Catholic at Christmas is that the Feast isn't over in just a day - we have the Octave of Christmas, followed by the Epiphany and its Octave, ending with the Feast of Our Lord's Baptism. We therefore have time to reflect on the awesome mystery of the Incarnation and its implications for us.
Here is a rather nice video of the first verse in Latin, accompanied by some beautiful astronomical images (just to stress the point that we scientists aren't all atheists, and that the wonders of the universe can, in fact, lead us to a greater appreciation of God).
I am also including a link to this version in English, which contains more of the verses with text of they lyrics, to help you appreciate the beauty of this hymn.
May God bless you and continue to grant you a Happy Christmas.