I'm only speaking about USA here; and regarding your statement about religion interfering with government.
When Thomas Jefferson was drafting the Declaration of Independence, he wanted to include statements of religion. Benjamin Franklin and John Adams talked him out of it. They were each religious people; but they were Deists. That means they did not belong to any church; but they were moral and believed in God. Later, the same concept happened when writing the Constitution. It is called Secular. Keep the Constitution and religion separate. Let's hope that continues forever. The Constitution was not modeled from the 10 Commandments either. It was modeled after British Common Law. That Law was created long before protestantism was introduced in England; but I think Catholic was known. It is only the personalities in power that allow religion to influence our (USA) government.
There. I think I said everything without stepping on toes.