My estimable co-blogger at American Creation, Rev. Gary Kowalski, wrote a post on John and Abigail Adams' love letters and it touched upon their admiration of the Revs. Joseph Priestley and Richard Price.
That's what the following excerpt focuses on:
More to their liking were the sermons of Richard Price, a dissenting clergyman whose services the two attended while on appointment to Great Britain. Although ordained a Presbyterian, Price’s doubts about the divinity of Jesus had turned him toward Unitarianism—like his friend Joseph Priestly, who succeeded him in the same pulpit. A superb mathematician, Price shared the Adams’ scientific interests. But when the reverend presided over the christening of their grandchild William, Abigail was so flustered that she had to take to her bed, causing her miss several of his lectures on “electricity, magnetism, hydrostatics” and other researches which she described as “going into a beautiful country … a country to which few females are permitted to visit or inspect.”
Dr. Price had been a strong supporter of the colonies in their revolt against England. In Observations on the Importance of the American Revolution, and the Means of Making It a Benefit to the World, published just after the war, Price argued that complete religious liberty ought to prevail in the new nation, along with a system of education that “teaches how to think, rather than what to think.” He spoke admiringly of the Massachusetts Constitution that John had written, guaranteeing that “every denomination of Christians demeaning themselves peaceably and as good subjects of the Commonwealth” should have equal protection of the laws. “This is liberal beyond all example,” Price declared, “I should however have admired it more had it been more liberal and the words all men of all religions been substituted for every denomination of Christians.”
“I am happy to find myself perfectly agreed with you, that we should begin by setting the conscience free,” John wrote back. It was the beginning of a lifelong friendship, and Abigail told their son John Quincy that traveling the few miles from London to Hackney each Sunday was well worth the effort, “to hear a man so liberal and so sensible and so good as he is.”
Their eldest son tended to be more traditional in his faith than either father or mother, but when the break occurred in New England that divided so many congregations down the middle, Abigail made her position clear. “I profess myself a Unitarian in Mr. Channings sense,” she told her son. “The soil of N England will not cultivate nor cherish clerical bigotry or intolerance although, there is a struggle to introduce it.” In a letter dated May 4, 1816, she staked out her non-trinitarian beliefs even more firmly, telling the junior Adams “There is not any reasoning which can convince me, contrary to my senses, that three is one, and one three,” adding in an aside to a friend that her husband considered their son an “Excellent politician, but no theologian.”