Some facts about Chrismas and its pass. The word Christmas originates from the words Christ's Mass. The date of December 25th was chosen in the 4th century. One of the main reasons we have the custom of giving and receiving presents at Christmas, is to remind us of the presents given to Jesus by the Wise Men: Frankincense, Gold and Myrrh. The evergreen fir tree has traditionally been used to celebrate winter festivals (pagan and Christian) for thousands of years. Pagans used branches of it to decorate their homes during the winter solstice, as it made them think of the spring to come.