It is already a proven fact, without any dispute whatsoever, the Founding Fathers considered us a Christian Nation. They wrote it several times in public pronouncements, and formed the States establishing Christianity:
If the public homage of a people can ever be worthy the favorable regard of the Holy and Omniscient Being to whom it is addressed, it must be that in which those who join in it are guided only by their free choice, by the impulse of their hearts and the dictates of their consciences; and such a spectacle must be interesting to all Christian nations as proving that religion, that gift of Heaven for the good of man, freed from all coercive edicts, from that unhallowed connection with the powers of this world which corrupts religion into an instrument or an usurper of the policy of the state...Upon these principles and with these views the good people of the United States are invited, in conformity with the resolution aforesaid, to dedicate the day above named to the religious solemnities therein recommended. [bold face mine]--Given at Washington, this 23d day of July, A. D. 1813.[seal.] JAMES MADISON
Note, Madison--the Orthodox Christian--like all his references about religion early in life, refers to religion as only Christianity.
Here is John Adams claiming we are a Christian people:
[T]hat they may consider what further measures the honor and interest of the Government and its constituents demand; if a resolution to do justice as far as may depend upon me, at all times and to all nations, and maintain peace, friendship, and benevolence with all the world; if an unshaken confidence in the honor, spirit, and resources of the American people, on which I have so often hazarded my all and never been deceived; if elevated ideas of the high destinies of this country and of my own duties toward it, founded on a knowledge of the moral principles and intellectual improvements of the people deeply engraven on my mind in early life, and not obscured but exalted by experience and age; and, with humble reverence, I feel it to be my duty to add, if a veneration for the religion of a people who profess and call themselves Christians, and a fixed resolution to consider a decent respect for Christianity among the best recommendations for the public service, can enable me in any degree to comply with your wishes, it shall be my strenuous endeavor that this sagacious injunction of the two Houses shall not be without effect.--First Inaugural, In the City of Philadelphia, Saturday, March 4, 1797.
This proves beyond any doubt Nature's God in the Declaration of Independence was the God of Abraham, Isaac, and Jacob. Adams helped draft the Declaration. When Virginia and Massachusetts formed Christianity as the established religion of their respective States, it wasn't Unitarianism they had in mind; it was what they allowed. In Massachusetts, the Unitarian Adams was part of the secret minority in 1780 who personally understood Christian Unitarianism was Christianity. Anyway, here is Fea:
When we think of the defenders of a Christian America today, the Christian Right immediately comes to mind. We think of people like Glenn Beck (who despite his Mormonism has joined forces with many Christian nationalists), David Barton, Peter Marshall and David Manuel, or Newt Gingrich. All of these public figures have championed the idea that the United States was founded as a Christian nation. Their careers have been defined by the belief that this country needs to return to its Christian roots in order to receive the blessings of God. Rarely, if ever, do we hear the name Martin Luther King, Jr., included in this list of apologists for Christian America. Yet he was just as much of an advocate for a "Christian America" as any who affiliate with the Christian Right today.Without getting into the subject of Martin Luther King Jr, who wasn't even a Christian, (He denied Biblical Inerrancy, The Deity of Jesus Christ, et al.) therefore he is irrelevant as any other heterodox framer, like Benjamin Franklin, in claiming we were formed a Christian Nation. Biblically speaking, King and Franklin's Christianity is not Christian. Politically speaking, Unitarianism or Arianism, may have been accepted under the umbrella of Christianity, however, the vast majority of Colonial Protestants were Orthodox, thus, the governing documents reflected their Orthodox sentiments, not those of Arianism or any other ism.
It was claimed by the framers themselves, not just David Barton, et al; that by violating the Scriptures, not only would the Blessings cease, but judgment was just around the corner:
As nations can not [sic] be rewarded or punished in the next world they must be in this. By an inevitable chain of causes & effects[,] providence punishes national sins, by national calamities.--The Father of the Bill of Rights. The Constitutional Convention. Robert A. Rutland, ed., The Papers of George Mason (Chapel Hill: The University of North Carolina Press, 1970), p.966.
George Mason was an Evangelical--as nearly all of them were--Christian Fundamentalist, who partook of the Communion elements that signified his belief in Christ's Vicarious Blood Atonement for Sin.
Noah Webster and James Madison were emphatic in defining terms correctly, otherwise subverting the Constitution could ensue. The Christian States allowed any practicing faith, Christian or not, that did not violate public order or the Scriptures.
Without showing my hand--something left for a book--the Founding Fathers wrote our governing documents in Orthodox language.