I think you're creating a false dichotomy that religion is separate from culture.  You can't separate atheism or humanism from culture either.  Canada was formed by two major cultural groups.  The country is redolent with the traditions of both nations.  To pretend that Canada would be the same country if it was settled by Indonesian islanders or atheist Maoist Chinese revolutionaries is wrong.  Cultural values set precedents in law and the legislation that is voted in by citizens and supported