Take the time to listen to this lecture. This is very useful knowledge.
The Separation of Church and State: "Onkar Ghate delivered this lecture on July 5, 2009, in Boston. With religion on the rise in America, maintaining the separation of church and state is now a pressing issue. This talk examines some of the history behind, as well as the arguments for and against, the principle of separating religion from government. It considers contemporary ways in which the principle is being attacked and why even well-meaning Americans are increasingly unable to mount a defense. Finally, it defines what a proper, philosophical argument for the need to separate church from state looks like."