All religions are political systems. They are all, essentially, little "governments", with laws that believers must follow to be accepted, and rules that limit contact with outsiders - food, dress, association with "unbelievers".  Until the time of David Hume and Adam Smith, Scotland was governed by the Catholic Church or the Church of Scotland, whoever was in power at the time, and the rules changed so frequently that Hume and other philosophers (many in France) shaped the philosophy of secular government, with separation of church and state. Religions that accept the supremacy of secular law do well in secular states. Catholics, Protestants and Jews have largely learned that lesson. Those that insist on the supremacy of their law ("I only follow the law of God") cause disruption and unrest within society. 
Ontario, under Dalton McGuinty, came within a hairsbreadth of establishing sharia law as a parallel legal system in Ontario.  It would have been a disaster.