John Adams was a complete heretic by Catholic standards. A Congregationalist by birth, he would eventually abandon belief in the Trinity and the divinity of Christ. Though a "church-going animal" Adams famously exclaimed in a letter to Thomas Jefferson:

"Twenty times, in the course of my late Reading, have I been upon the point of breaking out, ’This would be the best of all possible Worlds, if there were no Religion in it.'"

He would later backtrack that “without Religion this World would be Something not fit to be mentioned in polite Company, I mean Hell."

It appears he was ambivalent.