http://www.religioustolerance.org/xmas_tree.htm
Pagan traditions: Many Pagan cultures used to cut boughs of evergreen trees in December, move them into the home or temple, and decorate them. 7 Modern-day Pagans still do. This was to recognize the winter solstice -- the time of the year that had the shortest daylight hours, and longest night of the year. This occurs annually sometime between DEC-20 to 23; most often, it is DEC-21. As the solstice approached, they noticed that the days were gradually getting shorter; many feared that the sun would eventually disappear forever, and everyone would freeze. But, even though deciduous trees, bushes, and crops died or hibernated for the winter, the evergreen trees remained green. They seemed to have magical powers that enabled them to withstand the rigors of winter.
"The first decorating of an evergreen tree began with the heathen Greeks and their worship of their god Adonia, who allegedly was brought back to life by the serpent Aessulapius after having been slain." 5
The ancient Pagan Romans decorated their "trees with bits of metal and replicas of their god, Bacchus [a fertility god]. They also placed 12 candles on the tree in honor of their sun god" 2 Their mid-winter festival of Saturnalia started on DEC-17 and often lasted until a few days after the Solstice.
In Northern Europe, the ancient Germanic people tied fruit and attached candles to evergreen tree branches, in honor of their god Woden. Trees were viewed as symbolizing eternal life. This is the deity after which Wednesday was named. The trees joined holly, mistletoe, the wassail bowl and the Yule log as symbols of the season. All predated Christianity. 5
