[eli_gottlieb]

If that is true, then in a multicultural or multi-religion group no rights exist at all after time passes.

Well... kind of, yeah. In real life, most multicultural regions have codes of "rights and freedoms" designed as workable compromises between the moral philosophies of the various cultures living there. Once such a code exists, it will usually be amended rather than scrapped, and new arrivals made to conform somewhat (because it has become a shared culture), but that is, in fact, how it works.