The founding fathers recognized as their seminal mouthpiece of ideology the corpus of the writings of Thomas Paine who epoused deism which can be described by the comments made below which I find accurate and an indicator of the beliefs of the founding fathers though not necesarily the common people of the period.
He challenged the inerrancy of the bible, at a far distance of the true accounts of scripture as the life of Christ and his divinity7 as described in the NT are denied as "fabulous" and the fathers accepted for the most part this rendition. They are in no wise the "christians" they are claimed to be by the acsribed "fundamentalists of this present age and the evangelicals.
Note this is a thorough compilation of the soundbooks of The Age of Reason
The Age of Reason
The Age of Reason: Being an Investigation of True and Fabulous Theology, a deistic treatise written by eighteenth-century British radical and American revolutionary Thomas Paine, critiques institutionalized religion and challenges the inerrancy of the Bible. Published in three parts in 1794, 1795, and 1807, it was a bestseller in America, where it caused a short-lived deistic revival. British audiences, however, fearing increased political radicalism as a result of the French revolution, received it with more hostility. The Age of Reason presents common deistic arguments; for example, it highlights the corruption of the Christian Church and criticizes its efforts to acquire political power. Paine advocates reason in the place of revelation, leading him to reject miracles and to view the Bible as an ordinary piece of literature rather than as a divinely-inspired text. Yet, The Age of Reason is not atheistic: it promotes natural religion and argues for a creator-God. (Summary by Wikipedia)