Religion or Competition?

As we were talking about Christmas and how we don’t really know what day Jesus was born, I started thinking.  We discussed how Christians picked the date of Christmas to compete with the Romans’ celebration of Saturnalia.  It makes me wonder how much of our beliefs and practices come from competition between religions rather than pure belief and evidence.  I also wonder if Christians should really be celebrating many of the Jewish holidays that coincide with their beliefs and history.  In today’s world, I feel that we may not want to celebrate the same things as another religion because we want to be so separate and independent.  We can’t have anything to do with or of the same practices of another religion because we need to have more power or authority.  If we practice the same things, we are more equal.  Maybe I am just imagining some of this, but I feel today’s culture is all about competition and being better than another group or person.  I want to learn more about each religion’s practices in order to have an informed opinion about this.