Nowadays, we decorate our Christmas trees with lights, tinsel, adorable but overpriced ornaments from Hallmark, etc. However traditionally, the tree was decorated with edibles such as nuts and apples. The pine tree was selected to be the official plant of Christmas because evergreens symbolize immortality and fortitude due to their ability to thrive in the harshest of winters.
In Christian tradition, pine trees were often put up in December to ward off evil and act as a perch for whatever birds still remained. In the Middle Ages, they were used in Christmas Eve plays to represent the tree from which Adam and Eve took the forbidden fruit. German craftsman guilds during the Renaissance created the first decorations for Christmas trees, which started the tradition of decorating Christmas trees. So, Hallmark, you now know who to thank.