Thomas Jefferson, 1786
Well aware that Almighty God hath created the mind free; that all attempts to influence it by temporal punishments or burdens, or by civil incapacitations, tend only to beget habits of hypocrisy and meanness, and are a departure from the plan of the Holy Author of our religion, who being Lord both of body and mind, yet chose not to propagate it by coercions on either, as was in his Almighty power to do; that the impious presumption of legislators and rulers, civil as well as ecclesiastical, who, being themselves but fallible and uninspired men, have assumed dominion over the faith of others, setting up their own opinions and modes of thinking as the only true and infallible, and as such endeavoring to impose them on others, hath established and maintained false religions over the greatest part of the world, and through all time; that to compel a man to furnish contributions of money for the propagation of opinions which he disbelieves, is sinful and tyrannical; that even the forcing him to support this or that teacher of his own religious persuasion, is depriving him of the comfortable liberty of giving his contributions to the particular pastor whose morals he would make his pattern, and whose powers he feels most persuasive to righteousness, and is withdrawing from the ministry those temporal rewards, which proceeding from an approbation of their personal conduct, are an additional incitement to earnest and unremitting labors for the instruction of mankind; that our civil rights have no dependence on our religious opinions, more than our opinions in physics or geometry; that, therefore, the proscribing any citizen as unworthy the public confidence by laying upon him an incapacity of being called to the offices of trust and emolument, unless he profess or renounce this or that religious opinion, is depriving him injuriously of those privileges and advantages to which in common with his fellow citizens he has a natural right; that it tends also to corrupt the principles of that very religion it is meant to encourage, by bribing, with a monopoly of worldly honors and emoluments, those who will externally profess and conform to it; that though indeed these are criminal who do not withstand such temptation, yet neither are those innocent who lay the bait in their way; that to suffer the civil magistrate to intrude his powers into the field of opinion and to restrain the profession or propagation of principles, on the supposition of their ill tendency, is a dangerous fallacy, which at once destroys all religious liberty, because he being of course judge of that tendency, will make his opinions the rule of judgment, and approve or condemn the sentiments of others only as they shall square with or differ from his own; that it is time enough for the rightful purposes of civil government, for its officers to interfere when principles break out into overt acts against peace and good order; and finally, that truth is great and will prevail if left to herself, that she is the proper and sufficient antagonist to error, and has nothing to fear from the conflict, unless by human interposition disarmed of her natural weapons, free argument and debate, errors ceasing to be dangerous when it is permitted freely to contradict them.
Be it therefore enacted by the General Assembly, That no man shall be compelled to frequent or support any religious worship, place, or ministry whatsoever, nor shall be enforced, restrained, molested, or burdened in his body or goods, nor shall otherwise suffer on account of his religious opinions or belief; but that all men shall be free to profess, and by argument to maintain, their opinions in matters of religion, and that the same shall in nowise diminish, enlarge, or affect their civil capacities.
And though we well know this Assembly, elected by the people for the ordinary purposes of legislation only, have no powers equal to our own and that therefore to declare this act irrevocable would be of no effect in law, yet we are free to declare, and do declare, that the rights hereby asserted are of the natural rights of mankind, and that if any act shall be hereafter passed to repeal the present or to narrow its operation, such act will be an infringement of natural right.
Thomas Jefferson drafted The Virginia Act for Establishing Religious Freedom in 1779 three years after he wrote the Declaration of Independence. The act was not passed by the General Assembly of the Commonwealth of Virginia until 1786. Jefferson was by then in Paris as the U.S. Ambassador to France. The Act was resisted by a group headed by Patrick Henry who sought to pass a bill that would have assessed all the citizens of Virginia to support a plural establishment. James Madison's Memorial and Remonstrance Against Religious Assessments was, and remains, a powerful argument against state supported religion. It was written in 1785, just a few months before the General Assembly passed Jefferson's religious freedom bill. Both the draft version of the Virginia Act for Establishing Religious Freedom and the Memorial and Remonstrance Against Religious Assessments are availalbe on this site.
Source: The Religious Freedom Page - University of Virginia.