In May this year, Barton appeared on The Daily Show where he was confronted regarding his reading of the letter. Warren Throckmorton's post lays out the context that Barton ignores (because it reveals how wrong he is concerning Adams' meaning. In the blog entry, "David Barton and John Adams--The Holy Ghost Letter, Throckmorton offers some choice links to others who have refuted some of Barton's claims.
After a quick run through several blog entries, I went to the Online Library of Liberty to search the ten volume The Works of John Adams at Online Library of Liberty. I sought the Holy Ghost in this voluminous work, finding a mere six entries. One seems in the spirit of what Rodda, Throckmorton, and others are saying regarding Adams' presentation of views that he held in contempt: a letter to F.A Vanderkemp, 13 July 1815. The key paragraph states:
My friend, again! the question before mankind is,—how shall I state it? It is, whether authority is from nature and reason, or from miraculous revelation; from the revelation from God, by the human understanding, or from the revelation to Moses and to Constantine, and the Council of Nice. Whether it resides in men or in offices. Whether offices, spiritual and temporal, are instituted by men, or whether they are self-created and instituted themselves. Whether they were or were not brought down from Heaven in a phial of holy oil, sent by the Holy Ghost, by an angel incarnated in a dove, to anoint the head of Clovis, a more cruel tyrant than Frederic or Napoleon. Are the original principles of authority in human nature, or in stars, garters, crosses, golden fleeces, crowns, sceptres, and thrones? These profound and important questions have been agitated and discussed, before that vast democratical congregation, mankind, for more than five hundred years. How many crusades, how many Hussite wars, how many powder plots, St. Bartholomew’s days, Irish massacres, Albigensian massacres, and battles of Marengo have intervened! Sub judice lis est. Will Zinzendorf, Swedenborg, Whitefield, or Wesley prevail? Or will St. Ignatius Loyola inquisitionize and jesuitize them all? Alas, poor human nature! Thou art responsible to thy Maker and to thyself for an impartial verdict and judgment.Adams writes of holy oil direct from the Holy Ghost being used to anoint the heads of kings. But to say that he believes such stories strikes me as a stretch.
Adams to Vanderkemp, Accessed from http://oll.libertyfund.org/title/2127/193560/3102804 on 2011-06-11