"The founders set that up because they followed the biblical admonition on what a civil society is supposed to look like."

The obvious first point is of course that the founders, many very religious, went out of their way to set up a secular process of governance because they knew of both past and their current world where religion and government mixing caused lots of problems, and "the Great Experiment" was all about not following the same path this time.

I'm curious what Biblical passages he's pulling from. I'm leaning towards him just talking out his ass (because he can say anything to plenty of believers while invoking "the Bible says" and they'll nod in agreement without questioning), but I'm willing to give him a bit of benefit if he can find anything to support the claim.