The question is, was the United States founded as a religious nation? Was it meant to be a Christian nation, or just a nation with no official religion that happened to be populated with (mostly) Christians. Anyone with any familiarity with Enlightenment thinking about democracy and separation of church and state, and free thought, and the consent of the governed, and all the rest knows that the country was specifically founded without any official religion. They made a point of clarifying that in the Constitution. Anyone familiar with the writings of the founders knows this. I'm sure you know it too.
You can quote all the way back as far as you want, but it doesn't mean much. After all, those people believed in the Divine Right of Kings, but it doesn't make sense to say that the US was founded on allegiance to the Monarchy, so why do you get to cherry pick some things from 180 years prior to the founding, but not others? Why pick some religious beliefs but not others?