CHR Comment: National Geographic briefly describes two theories about the relationship between the winter solstice and the date of Christmas. A prevailing view is that Christians chose December 25 as the date to celebrate Jesus’ birth to offer a Christian alternative to celebrating the pagan Sol Invictus (Unconquered Sun) holiday that was timed with the winter solstice, the shortest day of the year. A more common Christian explanation is that the day was chosen since it is nine months after the day when the angel Gabriel announced to Mary that she would miraculously have a child who would be the Savior (Annunciation Day, March 25; Luke 1:26-37).
CHR Comment: The use of trees in Christmas celebrations first appeared in the medieval period in northern Europe, not during the era of the “Early Church” as the article states (the examples are from the Age of Orthodoxy after the Reformation). Christmas trees likely came from the customs of burning trees/logs during the darkest days of winter since the winter solstice falls near the time of Christmas (December 25). Although some church leaders opposed the use of the trees, others saw no harm in it. The second link, from the History Channel, provides further information.