Article VI, paragraph 3 of the U.S. Constitution declares, that 'no religious test shall ever be required as a qualification to any office or public … - Joseph Story

The real object of the First Amendment was, not to countenance, much less to advance Mahometanism, or Judaism, or infidelity, by prostrating Christianity; but to exclude all rivalry among Christian sects, and to prevent any national ecclesiastical establishment, which should give to an hierarchy the exclusive patronage of the national government. It thus cut off the means of religious persecution, (the vice and pest of former ages,) and of the subversion of the rights of conscience in matters of religion, which had been trampled upon almost from the days of the Apostles to the present age. The history of the parent country had afforded the most solemn warnings and melancholy instructions on this head; and even New England, the land of the persecuted puritans, as well as other colonies, where the Church of England had maintained its superiority, would furnish out a chapter, as full of the darkest bigotry and intolerance, as any, which should be found to disgrace the pages of foreign annals. Apostacy, heresy, and nonconformity had been standard crimes for public appeals, to kindle the flames of persecution, and apologize for the most atrocious triumphs over innocence and virtue.

Here shall the Press the People's right maintain,
Unawed by influence and unbribed by gain;
Here Patriot Truth her glorious precepts draw,
Pledged to Religion, Liberty, and Law.

I will not say with Lord Hale, that "the law will admit of no rival, and nothing to go even with it;" but I will say, that it is a jealous mistress, and requires a long and constant courtship. It is not to be won by trifling favours, but by a lavish homage.