It's funny. See this thread on worldmagblog, which illustrates that stubbornness is intractable in human nature. Someone possesses an erroneous assumption. They are given more than adequate evidence refuting the assumption. Yet, they stubbornly refuse to let go of their error.
In this case, it's a fellow named Joel Mark who assumed that John Adams was an orthodox Christian, and not a Unitarian, was shown overwhelming evidence to the contrary, complete with references to primary sources, yet still refuses to let go of the notion that Adams was a traditional minded Christian. In one comment directed at me, he wrote:
You are flat out wrong....John Adams was NOT a Unitarian. That was never how he identified himself or was identified and the Unitarians were not even around in Massachusetts or America in his prime years.
You are unreliable on this matter. maybe its just that your sources are poor. But you are wrong.
He further asks for "smoking gun" evidence demonstrating that Adams identified himself as a Unitarian. Ye ask, and ye shall receive. Here is Adams himself on the matter:
I thank you for your favour of the 10th and the pamphlet enclosed, "American Unitarianism." I have turned over its leaves and have found nothing that was not familiarly known to me.
In the preface Unitarianism is represented as only thirty years old in New England. I can testify as a Witness to its old age. Sixty five years ago my own minister the Reverend Samuel Bryant, Dr. Johnathan Mayhew of the west Church in Boston, the Reverend Mr. Shute of Hingham, the Reverend John Brown of Cohasset & perhaps equal to all if not above all the Reverend Mr. Gay of Hingham were Unitarians. Among the Laity how many could I name, Lawyers, Physicians, Tradesman, farmers!
John Adams to Jedidiah Morse, May 15, 1815. Adams Papers (microfilm), reel 122, Library of Congress.
We Unitarians, one of whom I have had the Honour to be, for more than sixty Years, do not indulge our Malignity in profane Cursing and Swearing, against you Calvinists; one of whom I know not how long you have been. You and I, once saw Calvin and Arius, on the Plafond of the Cathedral of St. John the Second in Spain roasting in the Flames of Hell. We Unitarians do not delight in thinking that Plato and Cicero, Tacitus Quintilian Plyny and even Diderot, are sweltering under the scalding drops of divine Vengeance, for all Eternity.
John Adams to John Quincy Adams, March 28, 1816, Ibid, reel 430.
These quotations are featured in James H. Hutson's fine book of quotations, pp. 220-221.