The tree is probably not Christian anyway, so feel free to consider it a Heathen tradition and sacrifice to Odin or something.
"Pagan traditions: Many Pagan cultures used to cut down evergreen trees in December, moved them into the home or temple and decorated 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. 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."