So, I learned a little bit about the tradition of the Christmas tree today! Please read:
The idea started when St. Boniface went to a town in Germany, I believe in the 8th century. He went to share the Gospel with them. He discovered they were worshipping an oak tree. One day, he saw some people were going to sacrifice a young prince to the "holy" tree. St. Boniface saved the boy and cut down the enormous tree! Since the people had such a fascination with trees (lol) he gave the example that God's love is everlasting--like the leaves of an evergreen tree which are always green. As a result, the tradition of putting evergreen trees in the house started to symbolize God's love.