“The divorce between the church and the state ought to be absolute. It ought to be so absolute that no church property anywhere in any State or in the nation should be exempt from equal taxation; for if you exempt the property of any church organization, to that extent you impose a church tax upon the whole community.”

where no Catholic prelate would tell the President (should he be Catholic) how to act, and no Protestant minister would tell his parishoners for whom to vote — where no church or church school is granted any public funds or political preference — and where no man is denied public office merely because his religion differs from the President who might appoint him or the people who might elect him.
1960, Speech to the Greater Houston Ministerial Association

The Church and the Ministry in the Early Centuries (1903), p. 360 http://books.google.com/books?id=IvUsAAAAMAAJ&pg=PA360

Hannity and Colmes (25 August 2003), as quoted in "The Document Sean Hannity Doesn't Want You To Read" at American Progress (16 June 2004) http://www.americanprogress.org/issues/kfiles/b91585.html

Letter to http://press-pubs.uchicago.edu/founders/documents/v1ch15s32.html James Madison (28 October 1785)
1780s

Source: Generation of Vipers (1942), p. 324
Context: There are in America from fifteen to twenty million religious fundamentalists who are dedicated to doctrines incompatible with democracy in that they insist on their prerogatives as first principles. An even larger group feebly follows the trail of fire breathed by those fundamentalists. They are the most dangerous minority we have because they categorically eschew the reasoned judgments of the majority. Democracy properly allows them the right to worship as they choose. It should never have conceded them the right to establish schools. Education is not a function of any church — or even of a city — or a state; it is a function of all mankind.

Source: 1790s, The Age of Reason, Part I (1794)

2000s, 2002, State of the Union address (January 2002)

Orthodoxy (1884)
Context: In 1473 Copernicus was born. In 1543 his great work appeared. In 1616 the system of Copernicus was condemned by the pope, by the infallible Catholic Church, and the church was about as near right upon that subject as upon any other. The system of Copernicus was denounced. And how long do you suppose the church fought that? Let me tell you. It was revoked by Pius VII. in the year of grace 1821. For two hundred and seventy-eight years after the death of Copernicus the church insisted that his system was false, and that the old Bible astronomy was true.

2010s, American Contempt for Liberty (2015)
Context: What our nation needs is a separation of “business and state” as it has a separation of “church and state.” That would mean crony capitalism and crony socialism could not survive.