The United States, by some reckoning, is among the most consistently religious countries on earth. More of us go to a house of worship on a regular basis than in most countries. The majority of us believe in a higher power. And we have both more religions and a higher level of religious tolerance than anywhere else on the planet. But is religion really an American value? And if so, why has the separation of church and state been held so fundamental since the days of Thomas Jefferson?