Having a king doesn't seem to hold us back in the UK too much. The king is Christian. Commonwealth countries are free to leave if they wish (and replace with their head of state of choice). Of the two top political jobs in the UK the First Minister of Scotland is a Muslim and the Prime Minister is Hindu. All three recently replaced women who fulfilled those roles (as women will again). We are free to peacefully practice any or no religion and vote for those who make laws. Can't think of another European country with as much recent diversity of representation, can you?