David Hume notes the extent to which, despite it’s religious overtones, much of what we know about Christmas is decidedly non-Christian:
Though Christians assert “Jesus is the reason for the season,” a more precise formulation might be that “Jesus became the reason for the season in the minds of some.” This is important. It is not without rationale that Christian groups like the Jehovah Witnesses reject Christmas, it is not a scriptural festival. Its emergence in the 4th century coincided with the synthesis of Christianity with Roman Imperial culture as the latter took upon the former as the state religion. In 274 the Roman Emperor Aurelian dedicated a temple to the sun god, Sol Invictus, on the 25th of December, Natalis Sol Invictus, “the birth of the invincible sun.” Interestingly, many early depictions of Jesus Christ co-opted solar imagery (e.g., the halo around the Christ). It seems that the thrusting forward of December 25th as the birth of Christ was strongly motivated by co-option of a pre-existing festival. Additionally, holiday merry-making seems to have its classical antecedants in Saturnalia. But this tendency of a mid-winter festival is not limited to Southern Europe. Yule and its cousins play an even greater role in the north than they do in the sunny Mediterranean. The darkness of the mid-winter solstice festivals bloom to usher in the season of hope and lengthening days. Customs like the Yule Log, Christmas cookies and gift exchange all emerge out of this pre-Christian substratum. This is was not unknown to the Christian Church, during the medieval period there were futile attempts to suppress some of these practices. A great enough frustration broke out during the Reformation that groups like the Puritans banned the celebration of Christmas, which was after all a minor holiday next to Easter.
And then, of course, there’s the whole commercial side of the holiday and the fact that it’s pretty unlikely that Jesus Christ was actually born in December.
The funny thing is that all of these things are self-evident and yet to listen to the Bill O’Reilly’s of the world, you’d think that those horrible pagans were making an assault on the pure Christian holiday of Christmas.
In reality, it was the other way around.