"What a strange distinction! It certainly would have been foreign to the Founders, who thought the moral precepts of Christian faith indispensable to the survival of the infant republic. And it's a distinction that remains foreign to the vast majority of Americans today."
This claim is insupportable. Most of the founders believed that a reasonable or civil religion was necessary for good government but this was not revealed religion and certainly not "the moral precepts of Christian Faith." The civil religion most Founders thought important for politics did without the first four of the ten commandments.
Toward the end of their article, Novak and Levenick return to this point:
"Every single one of the Founders believed that, at the level of both individual morality and public policy, the demands of reason and of revelation powerfully reinforce one another. They understood that with respect to the ultimate questions -- the creation of the universe, the purpose of human existence, and the hope of life after death -- faith and philosophy might differ. In the practical world they inhabited, however, the Founders believed that both Socrates and Jesus enjoined their followers to accord all persons truth, justice, and charity."
It is true that on the surface some of the dictates of reason and some of the dictates of revealed religion overlap but this does not mean that the United States was founded on the dictates of revealed religion or Christianity. On the contrary, Washington appears to have been indifferent to revealed religion and Jefferson and Franklin were hostile to it. But we can look beyond the Founders to judge the religious character of the founding. At the time of the Founding perhaps no more than 20% of Americans belonged to a Church. America became a Christian nation and religious after the Founding. Church membership increased throughout the nineteenth-century. The figure for Church membership today is several times higher than it was at the Founding.
This last point is worth pondering. It leads one to suspect that, precisely because America is now more Christian and religious than it was at its founding, some people feel the need to make the Founding appear more Christian and religious than it was.
Finally, I would like to note that on the profound difference between reason and revelation with regard to questions of morality and the foundations of politics, a wonderful guide is Thomism and Aristotelianism: A Study of the Commentary by Thomas Aquinas on the Nicomachean Ethics by Harry Jaffa. The epigraph of the book is a quote from Winston Churchill: "It is baffling to reflect that what men call honour does not correspond always to Christian ethics."