Benjamin Franklin letter to Ezra Stiles, March 9 1790 wrote:
I believe in one God, creator of the universe. That he governs it by his Providence. That he ought to be worshiped. That the most acceptable service we render to him is doing good to his other children. That the soul of man is immortal, and will be treated with justice in another life respecting its conduct in this. These I take to be the fundamental principles of all sound religion, and I regard them as you do in whatever sect I meet with them.
As to Jesus of Nazareth, my opinion of whom you particularly desire, I think the system of morals, and his religion, as he left them to us, the best the world ever saw, or is likely to see; but I apprehend it has received various corrupting changes, and I have, with most of the present dissenters in England some doubts as to his divinity; tho' it is a question I do not dogmatize upon, having never studied it, and think it needless to busy myself with it now, when I expect soon an opportunity of knowing the truth with less trouble. I see no harm, however, in its being believed, if that belief has the good consequence, as it probably has, of making his doctrines more respected and better observed; especially as I do not perceive that the Supreme takes it amiss, by distinguishing the unbelievers in his government of the world with any particular marks of his displeasure.
I shall only add, respecting myself, that, having experienced the goodness of that being in conducting me prosperously thro' a long life, I have no doubt of its continuance in the next, though without the smallest conceit of meriting such goodness. My sentiments on this head you will see in the copy of an old letter enclosed, which I wrote in answer to one from a zealous religionist, whom I had relieved in a paralytic case by electricity, and who, being afraid I should grow proud upon it, sent me his serious though rather impertinent caution.
P.S.... I confide that you will not expose me to criticism and censure by publishing any part of this communication to you. I have ever let others enjoy their religious sentiments, without reflecting on them for those that appeared to me unsupportable and even absurd. All sects here, and we have a great variety, have experienced my good will in assisting them with subscriptions for building their new places of worship; and as I have never opposed any of their doctrines, I hope to go out of the world in peace with them all.
There is no doubt that Franklin was a devout Christian, at least at some point in his life.
Thomas Jefferson wrote:Believing with you that religion is a matter which lies solely between Man & his God, that he owes account to none other for his faith or his worship, that the legitimate powers of government reach actions only, & not opinions, I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should "make no law respecting an establishment of religion, or prohibiting the free exercise thereof," thus building a wall of separation between Church & State.
Jefferson said it simply to convey that it was not Government's place to establish religion, it was up to the individual (which is why the whole quote is important).