Christians celebrate actually on festival day of Mithras. Mithraists Three times a day they worshiped, with special weekly ceremonials on the day of the sun-god and with the most elaborate observance of all on the annual festival of Mithras, December twenty-fifth. 
Modern peoples continue reveling in the lavish distribution of Christmas gifts, and rich men endow great institutions of philanthropy and learning. This make tham feel great men. 
The Maypole, the Christmas tree, and the superstitious practice of rapping on wood perpetuate certain of the ancient customs of tree worship and the later-day tree cults.