One guy writes that Glenn Beck teaches "his viewers the much-debunked idea that America's creation was rooted in Christianity." In response, another guy writes that it was so founded on Christianity.
But no serious scholar of the period agrees with either of these disputants. The American Founding was along-simmered stew containing a variety of ingredients, amongst which 1) classical republicanism, 2) non-conformist Protestant ideology, and 3) Deist-tending Enlightenment philosophy were the most potent. Of course, any partisan can dig up a bunch of quotes from 2) and "demonstrate" that we are a Christian nation, or, from 3), to "debunk" that claim.
And neither side, I'd guess, has any interest in hearing the truth. "Well, it's complicated," is not a position that can easily be turned into propaganda to hurl at your political foes.