Traditionally, trees have been used as symbols of life and renewal, which is why they have been used in many different religions and cultures throughout history. In the case of Christmas, evergreens were chosen as symbols of eternal life, and they have been a part of the holiday for centuries. The tradition of decorating the tree with lights and ornaments is believed to have originated in Germany in the 16th century, and it is now a beloved part of the Christmas season around the world.