We have a Christmas tree because it's a tradition that originated from the ancient Germanic pagan practice of decorating evergreen trees during the winter solstice. The evergreen tree symbolized life and renewal, despite the harsh winter conditions. Over time, this tradition evolved into a symbol of the Christmas holiday, representing hope, joy, and the promise of new beginnings. We decorate the tree with lights and ornaments to remind us of the light and warmth of the holiday spirit.