It’s the reason for the season! Paganism. Jesus wasn’t born on Dec. 25. Researchers have speculated that the Roman Catholic Church chose Dec. 25 because it ties in with the winter solstice and Saturnalia, a festival dedicated to the Roman deity Saturn. The church could also co-opt this popular pagan festival, as well as the winter celebration of other pagan religions, by choosing this day to celebrate Jesus’ birthday
Pagans in Europe decorated their homes with evergreen branches during the winter solstice to symbolize new life and fertility. The Druids, the priests of the ancient Celts, decorated their temples with evergreen boughs to symbolize everlasting life.
Tree worship was common among pagan Europeans and survived into Scandinavian customs. For example, Scandinavians decorated their houses and barns with evergreens at New Year to scare away the devil.
The Christmas tree tradition emerged from the “sacred trees” of Northern European mythology such as Yggdrasil, the giant ash tree at the center of the Norse cosmos that holds all the worlds in its roots and branches.