Rob Tillett at Astrology.com has a wonderful article about the origins of the Christmas holiday. Here is a portion of the article:
In the New Testament, the holy book of the Christians, there is no actual mention of the date of the birth of Jesus and the primitive church did not celebrate it. The shepherds of Luke’s gospel (Luke 2:8) were said to have been minding their sheep in a field when they received the angelic proclamation of his birth. It is therefore unlikely that the birth of Jesus could have happened on December 25, for at that time all would have been wrapped up in a warm barn, the wintry weather being too cold for them to be out in the elements.
Why then was December 25 chosen as the day for Christmas? Here we have to look more deeply at the customs, religious practices and celebrations of the time.
The Solstice and the Saturnalia
At the beginning of the Christian Era, the Roman Empire was the dominant force in Europe, the Middle East and the world of the Mediterranean. Rome followed a pagan religion of many gods and goddesses, including Jupiter, Venus, Mercury, Mars, Saturn, the Moon and the Sun. There are many myths and legends that tell the stories of these gods and heroes, really a coded set of narratives that reveal much about the ancient cultures and their approach to life, the universe and everything.
Life in ancient times was far more dependent upon the seasons and the natural cycles than we are in the West today, cocooned as we are in our electronic villages, turning night into an interminable electric day. During times when people could actually see the stars in the night sky, astrology developed as a mode of making sense of these natural cycles and certain times in the year were seen to be especially significant.
The Cardinal Cross
Key times for celebration were the cardinal points of the seasons, the solstices in June and December and the equinoxes in March and October. These temporal points were utterly central to the the social mores of the ancients, as they not only measured the seasons, the sowing and reaping of crops, but also symbolised stages in the development of the soul. These calendrical festivities were seen as times when the fabric of the cosmos was loosened and the hand of divine providence could be moved to take a more active part in the lives of those who lived on the body of Mother Earth.
The solstice at Christmas time marks the entry of the Sun into the sign of Capricorn, the sign ruled by Saturn. On this day the Sun appears to halt over the tropic of Capricorn for three days [some take this to be the origin of the resurrection of Jesus after three days, corresponding to the resurrection of the Sun after three days] and then begins his journey North, marking the return of glorious light to the darkness of Winter in the Northern Hemisphere (Capricorn was known to the ancient Greeks as the Augean Stables – so effectively the Sun is born in a stable).
In Ancient Rome, the mythical age of Saturn’s reign was a golden age of happiness, without theft or servitude, and without private property. Saturn, dethroned by his son Jupiter, had joined Janus as ruler in Italy, but when his time as earthly king was up, he disappeared. “It is said that to this day He lies in a magic sleep on a secret island near Britain, and at some future time … He will return to inaugurate another Golden Age.”
Janus is said to have instituted the Saturnalia leading up to the solstice as a yearly tribute to his friend. For mortals, the festival provided a yearly symbolic return to the Golden Age. Thus, it was an offence during this period to punish a criminal or start a war. The meal normally prepared only for the masters was prepared and served first to the slaves by the masters. All people were equal and, because Saturn ruled before the current cosmic order, Misrule with its lord, Saturnalia Princeps was the order of the day.