What follows is an address by the late Bible Answer Man, Dr. Walter Martin, on "the cults." Dr. Martin was a key figure in modern fundamentalist-evangelicalism who posited a paradigm that defined non-orthodox Trinitarian systems as "non-Christian cults." As such, Mormons, Jehovah's Witnesses and other non-Nicene "Christians" were in fact, not "Christians," but members of "non-Christian" cults.
Martin criticized what he saw as errors in Roman Catholicism, but didn't term them "non-Christians" because of Catholics' embrace of Nicene orthodoxy.
Taking Dr. Martin's paradigm as a given, I want those sympathetic to his point of view to understand that according to this standard, America's key Founders (certainly J. Adams, Jefferson, Franklin, probably Washington, Madison, G. Morris, Hamilton before his deathbed, and many others) and the philosophers they followed (Newton, Locke, Milton, Clarke, Priestley, Price, Burgh, and many others) were not "historic Christians," but, like the Mormons and Jehovah's Witnesses, members of a "non-Christian cult," that oft-tried to pass itself off as "Christianity."
What is truly appalling is the way the John Ankerberg show -- a key promoter of Dr. Martin's theological understanding -- featured David Barton to mislead Ankerberg's/Martin's otherwise spiritually discerned audience/point of view on America's Founding political-theological heritage.
Note to Dr. Ankerberg's audience: Much of what Barton cites -- and much of the historical record that talks up the "religion" or "Christianity" of America's Founding -- actually invokes a non-Trinitarian and/or anti-Trinitarian theology. And, accordingly, the paradigm (the promoters of which say the Bible itself!) that defines non-Trinitarians out of "Christianity," concludes, by logical necessity, that these utterances may actually be to a "non-Christian cult."
I'd like to see more evangelicals/fundamentalists (or others) recognize this and define the political theology of the American Founding as, along with Mormonism and Jehovah's Witnessism, a non-Christian cult. Or at least be honest enough to recognize that, though orthodoxy abounded in that era, there was enough non-Christian cultic elements from folks like Locke, Newton, Clarke, J. Adams, Jefferson, Franklin, Priestley, Price intermixed that it is impossible to term America's Founding "Christian" in the minimal way that you understand the term.