Speaking of Germany, the back-and-forth development with regards to the separation of state and church there has to do with multiple religions (or sects if you will). Bismarck's Prussia was dominated by Lutherans, and as Prussia and its power grew, there was conflict with the ever more Catholic subjects and, more importantly, the Vatican. So the separation of state and church was launched by the Lutherna conservative elite to curb the Vatican's influence (this was the original Kulturkampf). However, eventually, the Catholics won overhand on the conservative side (Hitler came from the Catholic south too), and their party, the Centre Party, which started as Bismarck's most potent opposition, was then the main root of the West German CDU, which did it best to lessen the separation of church and state.

_{*Lunatic*, n.
One whose delusions are out of fashion.}