Well, the holiday originated to bring "light" and festivities to the winter solstice, which is the shortest day of the year in the Northern
hemisphere. Many of the christmas tradititions originated in medieval europe where villagers would burn trees to light up the night and roll "yule"
logs down hill while on fire. They would also give each other presents to celebrate this other wise gloomy day.
Only after the inquisitions did the protestants really start celebrating the birth of Jesus during this same solstice time. It was pretty ingenius and
now christmas is known more for the religious aspect than the literal origin of bringing cheer during the winter.
It is funny that any biblical historian could tell you that the description of Jesus' birth places it during the rainy season or spring.
Winter Solstice
Medieval solstice traditions
More xmas origin facts