America was founded on Christian principles?

I admit that many of the founding fathers were Christian, some were deists. Most of the citizens who made up the original 13 colonies were also Christian. Therefore, I do feel it is some what reasonable to say America was built on Christian foundations. But I don't think that America was built on the Christianity of the middle ages. It was a Christianity that had been heavily influenced by Renaissance. Every Christian civilization that existed prior to the Renaissance was brutal and looked no different than middle east looks today. Rome, Russia, England, France, all Christian countries with brutal histories. I think it's a little disingenuous to credit Christianity with the founding of America, and to ignore the 300 years of philosophical thought that made ideas like democracy and freedom possible. I certainly do not think that the founding fathers, even the Christian ones, were Bible t evangelicals.