Schultz has a piece about a letter Ben Franklin wrote to Thomas Paine but doesn't link to it. So here.....Read it. You'll find that Franklin neatly sums up what some of the later French philosophers said of the Enlightenment, mainly that without religion a society loses both its moral compass and a floor upon which to stand and the result will eventually be......no country. Franklin:

For without the belief of a Providence, that takes cognizance of, guards, and guides, and may favor particular persons, there is no motive to worship a Deity, to fear his displeasure, or to pray for his protection.