"I now make it my earnest prayer the God would have you and the State over which you preside, in His holy protection, that he would incline the hearts of the citizens to cultivate a spirit of subordination and obedience to government; to entertain a brotherly affection and love for one another, for their fellow citizens of the United States at large, and particularly for their brethren who have served in the field; and, finally, that he would be most graciously pleased to dispose us all to do justice, to love mercy, and to demean ourselves with that charity, humility, and pacific temper of mind, which were the characteristics of the Divine Author of our blessed religion, and without an humble imitation of whose example in these things we can never hope to be a happy nation." - George Washington letter , June 8, 1783
"whatever strikes at the root of Christianity tends manifestly to the dissolution of civil government." - People vs Ruggles, US Supreme Court, 1811 in which a man profaned Jesus Christ
"Of all the dispositions and habits which lead to political prosperity, Religion and Morality are indispensable supports. In vain would that man claim the tribute of patriotism, who should labour to subvert these great Pillars of human happiness, these firmest props of the duties of men and citizens. The mere politician, equally with the pious man ought to respect and to cherish them. A volume could not trace all their connections with private and public felicity. Let it simply be asked where is the security of property, for reputation, for life, if the sense of religious obligation desert the oaths, which the instruments of investigation in Courts of Justice? And let us with caution indulge the supposition, that morality can be maintained without religion. Whatever may be conceded to the influence of refined education on minds of peculiar structure, reason, and experience both forbids us to expect that National morality can prevail in exclusion of religious principle." - Washington's Farewell Address, Sept 19, 1796
"Certainly no power to prescribe any religious exercise, or to assume authority is religious discipline, has been delegated to the general government. It must then rest with the states, as far as it can be in any human authority." - Thomas Jefferson, Jan 23, 1808
"Believing with you that religion is a matter which lies solely between man and his God, that he owes account to none other for his faith or his worship, that the legislative powers of government reach actions only, and 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 and State." Thomas Jefferson Jan 1, 1802 in response to the Danbury Baptist Association's concern that the United States government was about to declare another denomination as the "official" church of the country.
This is what they were protecting against ... an official church of the state like England had.
"Here is my creed. I believe in one God, Creator of the Universe. That He governs it by His providence. That He ought to beworshipped. That the most acceptable service we render 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 conduct in this. These I take to be the principal principles of 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 ever saw or is likely to see; but I apprehend it has received various corrupt changes and I have, with most of the present dissenters in England, some doubts as to his Divinity; though it is a question I do not dogmatize upon, having never studied it, and I think it needlessl 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 probably it has, of making his doctrines more respected and better observed; especially as I do not percieve that the Supreme [Being] takes it amiss, by distinguishing the unbelievers in His government of the world with any particular marks of His displeasure..." Ben Franklin, to Ezra Stile, president of Yale University
"Suppose a nation in some distant region should take the Bible for their only law-book, and every member would be obliged, in conscience, to temperence and frugality and industry; to justice and kindness and charity towards his fellow men; and to piety, love and reverence towards Almighty God. In this commonwealth, no man would impair his healht by gluttony, drunkenness, or lust; no man would sacrifice his most precious time to cards or any other trifling and mean amusement; no man would steal, or lie, in any way defraud his neigbor, but would live in peace and good will with all men; no man would blaspheme hi Maker or profane his worship; but a rational and manly, a sincere and unafected piety and devotion would reign in all hearts. What a utopia; what a paradise would this region be!" - the diary of John Adams, Feb 22, 1756
"'Our different sentiments on almost every question is methinks a meloncholy proof of the imperfection of human understanding. We indeed seem to feel our own want of political sidom, since we have been running about in search of it...I have lived,sir, a long time, and the longer I live, the more convincing proofs I see of this truth-- that God governs in the affairs of men. And if a sparrow cannot fall to the ground without His notice,is it probable that an empire can rise without His aid? We have been assurde, Sir, in the sacrted writings, that 'except the Lord building the house, they labour in vain that build it.' I firmly believe this; and I also believe that without His concurring aid we shall succeed in this political building no better than the builders of Babel: We shall be divided by our little partial local interests; our projects will be confounded, and we ourselves shall become a reproach... I therefore beg leave to move-- that henceforth paryers imploring the assistance of Heaven, and its blessings on our deliberations be held in this Assembly every morning before we proceed to business..." - Ben Franklin