SW:
it's a Christian country. Case closed.
The Treaty of Tripoli, ratified by the U.S. Senate in 1797. Article 11 states: the United States of America is not, in any sense, founded on the Christian religion; as it has in itself no character of enmity against the laws, religion, or tranquility [sic], of Mussulmen [Muslims]; and, as the said States never have entered into any war, or act of hostility against any Mahometan nation, it is declared by the parties, that no pretext arising from religious opinions, shall ever produce an interruption of the harmony existing between the two countries."
the tenth president, John Tyler, in an 1843 letter: "The United States have adventured upon a great and noble experiment, which is believed to have been hazarded in the absence of all previous precedent — that of total separation of Church and State. No religious establishment by law exists among us. The conscience is left free from all restraint and each is permitted to worship his Maker after his own judgment. The offices of the Government are open alike to all. No tithes are levied to support an established Hierarchy, nor is the fallible judgment of man set up as the sure and infallible creed of faith. The Mohammedan, if he will to come among us would have the privilege guaranteed to him by the constitution to worship according to the Koran; and the East Indian might erect a shrine to Brahma, if it so pleased him. Such is the spirit of toleration inculcated by our political Institutions."
What does the Constitution say? Article VI states that "no religious test shall ever be required as a qualification to any office or public trust in the United States." Then there is the First Amendment: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof … "
"[O]ur form of government has no sense unless it is founded on a deeply felt religious faith," said Dwight Eisenhower, "and I don’t care what it is."