There are only three ways in which government and religion can interact:
1) Government can reject religion: the end result is the unrestrained rationalization of each choice by leaders such as, Mao, Stalin, Hitler, North Korea...etc
2) Government can embrace a single religion: The end result is better than option "1" as the leaders are constrained by the religions that empower them, but the result is still poor as the Islamic nations of the world currently prove. History likewise points to choosing singular faiths within Christianity as a poor choice as well, as does WWII Japan's choice.
3) Lastly, government can embrace all religions allowing social choices regarding those religions to be reflected through governance via the political process: This was the choice of the founders of the US. The result of this historically secular choice can be seen in the US until the last 40 years, during which liberals, Democrats, Communists, and progressives have pushed for option "1".
polifrog