Christmas trees are a common symbol of the holiday season, but their origin is somewhat debated. Some believe that the Christmas tree was first used by German Christians in the 16th century as a symbol of the "everlasting life" mentioned in the Bible. Others argue that the tradition was started by pagan groups who worshiped trees. Despite the debate, Christmas trees have become a beloved symbol of the holiday and are often decorated with lights and ornaments to create a warm and festive atmosphere.