Gene Edward Veith of World Magazine helps clear up some mythology about the so-called origins of Christmas in a pagan Winter Solstice festival:
True, the Emperor Aurelian, in the five short years of his reign, tried to start (a winter solstice festival), “The Birth of the Unconquered Sun,” on Dec. 25, 274. … But Aurelian’s new festival was instituted after Christians had already been associating that day with the birth of Christ. … Christians were not imitating the pagans. The pagans were imitating the Christians.
And Douglas Wilson helpfully tells us something about where all the pine boughs came from:
(T)he Christmas wreath custom did not come from paganism, but from a remarkable defeat of paganism. Boniface (680-754), missionary to the Germans, had chopped down a great oak, sacred to Thor. Three days later, on the first Sunday of Advent, he prevented a human sacrifice and used the sacrificial knife of the Druid priest to cut fir boughs for the people to take home as a reminder of Calvary. And of course, the inventor of Christmas tree lights (non-electric) was Martin Luther.