Though Jesus' birth is celebrated on December 25, most scholars agree that it is unlikely he was actually born on this date. The choice of December 25 for the Church's celebration of the Nativity is most likely to have been in order to squelch attendance at pagan solstice festivals falling on the same day.
This article would seem to contradict that....
Time was when I, like most people, took it for granted the winter solstice and, in particular, the Roman Feast of the Birth of the Unconquered Sun were simply pagan celebrations that hung around into Christian times. In fact, when I set out to write this book I still thought this. But I discovered the reality is far more complicated and interesting. Indeed, it turns out this widely assumed "fact" that "everybody knows" is probably another sample of pseudo-knowledge. For according to William Tighe, a church history specialist at Pennsylvania's Muhlenberg College, "the pagan festival of the 'Birth of the Unconquered Sun' instituted by the Roman Emperor Aurelian on 25 December 274, was almost certainly an attempt to create a pagan alternative to a date that was already of some significance to Roman Christians. Thus the 'pagan origins of Christmas' is a myth without historical substance."
- Interesting, though I would look at this a little differently - of course there are pagan precedents to Orthodox practice - there are many forms of religious life which constitute a kind of "universal grammar" of religious understanding (read Eliade, for example). Justin Martyr explain this by means of the idea of the "logos spermatikos" - the seeds of the Word scattered throughout creation. The Word is the creator, and it certainly makes sense that some memory of divine providence would be remembered in the world, and even discerned through the natural rotations of the spheres. The key here is that the real question isn't "which came first" but that the birth of the Son of God is shadowed in the myriad festivals of light that take place throughout the world after the winter soltice, when light once again begins to triumph over the darkness. Blessed Nativity! — FrJohn (talk) 19:32, December 24, 2006 (PST)