That there is such a Person as The Devil is no part of my Faith, nor that of many other Christians; nor am I sure that it was the belief of any of the christian Writers. Neither do I believe the doctrine of demoniacal possessions, whether it was believed by the sacred Writers or not; and yet my unbelief in these Articles does not affect my faith in the great facts of which the Evangelists were eye and ear witnesses.

John Adams, letter to Thomas Jefferson, March 3, 1814

It has been by wandering from the immutable laws of science, and the light of reason, and setting up an invented thing, called revealed religion, that so many wild and blasphemous conceits have been formed of the Almighty.

Thomas Paine, The Age of Reason Part Two, 1795

The Church of Rome has made it an Article of Faith that no man can be saved out of their Church, and all other religious Sects approach to this dreadfull opinion in proportion to their Ignorance, and the Influence of ignorant or wicked Priests.

John Adams, from his diary, February 16, 1756

I do not believe that any two men, on what are called doctrinal points, think alike who think at all. It is only those who have not thought that appear to agree.

Thomas Paine, The Rights of Man Part Two, 1792

I expect our principle contributions [for building a black church] will come from the Deists, swearing captains of vessels, and brokers of our city. The clergy and their faithful followers of every denomination are too good to do good.

Benjamin Rush, letter to Julia Rush, July 16, 1791

There is in human Nature a solid, unchangeable and eternal Foundation of Religion. There is also a germ of superstition, seemingly a fungous growth or a spurious sprout, which the grossest Blockheads and most atrocious Villains are able to cultivate into Systems and Sects to deceive millions and cheat and pillage hundreds and thousands of their fellow Creatures.

John Adams, letter to John Quincy Adams, May 10, 1816

That humans have an innate tendency to believe in a religion is something I can believe. I just personally think it’s part of the superstition, which is much more than a germ.

Christianity is an active, affectionate and social religion, chiefly consisting in a discharge of duties to our fellow creatures. It therefore requires no separation from them. Tho enjoining that we “be not conformed to the world,” in following this direction, the utmost attention is necessary lest distinctions from others by plainness of manners and customs assume the place of virtues, and become snares. Such distinctions are not in the least value in themselves because they are no part of the Divine Laws.

John Dickinson, Religious Instruction for Youth

Dickinson was a noted pamphleteer and defender of the Constitution. I do not have a date for this.

Religious bondage shackles and debilitates the mind and unfits it for every noble enterprize every expanded prospect.

James Madison, letter to William Bradford, April 1, 1774

The following Question may be answered some time or other - viz. Where do we find a precept in the Gospell, requiring Ecclesiastical Synods, Convocations, Councils, Decrees, Creeds, Confessions, Oaths, Subscriptions and whole Cartloads of other trumpery, that we find Religion incumbered with in these Days?

John Adams, from his diary, February 18, 1756

The most detestable wickedness, the most horrid cruelties, and the greatest miseries that have afflicted the human race, have had their origin in this thing called revelation or revealed religion.

Thomas Paine, The Age of Reason Part 2, 1795