William Livingston represents the truth that one errs when one looks superficially at the denominations America's Founders were associated with to try and determine what their religious convictions were.
The source of this common error is M.E. Bradford who derived the statistic using that formula, that 52 of the 55 members of the Constitutional Convention were "orthodox Christians." I don't blame him too much for it. For him, this seemed to be a minor aside. Rather it was other, later Christian Nationalists who tried to run with the ball and turn it into a "meme."
Livingston was formally associated with the Presbyterians. That means then he was a good Calvinist who believed in TULIP and the Westminster and every other creed and confession associated with them, right?
Livingston, in fact, was a self professed "Primitive Christian," who believed in Jesus as Messiah (with NO evidence of believing in the Trinity) and the Old and New Testament, and nothing else.
There is nothing in Livingston's writings that laud the term "orthodox," in fact, to the contrary. As he wrote, "I believe that the word orthodox, is a hard, equivocal, priestly term, that has caused the effusion of more blood than all the Roman emperors put together."
A good Whig, Livingston hated doctrinal Anglicanism, especially the "Athanasian Creed," which is formally endorsed by not only the Anglicans, but also the Presbyterians (the group he was affiliated with!). This led me to conclude previously, perhaps accurately, Livingston a theological unitarian.
This is how Livingston described his creed:
“Primitive Christianity short and intelligible, modern Christianity voluminous and incomprehensible,” The Independent Reflector, no. XXXI, June 28, 1753.