Pluarism is a great concept.  In theory it accommodates the ideals and values of many different people in a single society. As the US has evolved from Eurocentric society into one that embraces people from all over the world, the ideals of our revolution have been tested and expanded. Over time, the limits of concepts like religious freedom have moved with the acceptance and inclusion of various different groups of people.
When do these moving targets become a matter for employers? Here is an entertaining, but instructive example.
While the courts have yet to take the claimant seriously, the tale illustrates the care any employer must take when confronted with employee demands for consideration of beliefs that may seem off the wall. The comments at the end give useful guidance if you find yourself facing a different bowl of noodles.