You ask that Mr. Taft shall "let the world know what his religious belief is." This is purely his own private concern; it is a matter between him and his Maker, a matter for his own conscience; and to require it to be made public under penalty of political discrimination is to negative the first principles of our Government, which guarantee complete religious liberty, and the right to each to act in religious affairs as his own conscience dictates. Mr. Taft never asked my advice in the matter, but if he had asked it, I should have emphatically advised him against thus stating publicly his religious belief.
The demand for a statement of a candidate’s religious belief can have no meaning except that there may be discrimination for or against him because of that belief. Discrimination against the holder of one faith means retaliatory discrimination against men of other faiths. The inevitable result of entering upon such a practice would be an abandonment of our real freedom of conscience and a reversion to the dreadful conditions of religious dissension which in so many lands have proved fatal to true liberty, to true religion, and to all advance in civilization.
To discriminate against a thoroughly upright citizen because he belongs to some particular church, or because, like Abraham Lincoln, he has not avowed his allegiance to any church, is an outrage against that liberty of conscience which is one of the foundations of American life. You are entitled to know whether a man seeking your suffrages is a man of clean and upright life, honorable in all of his dealings with his fellows, and fit by qualification and purpose to do well in the great office for which he is a candidate; but you are not entitled to know matters which lie purely between himself and his Maker. If it is proper or legitimate to oppose a man for being a Unitarian, as was John Quincy Adams, for instance, as is the Rev. Edward Everett Hale, at the present moment Chaplain of the Senate, and an American of whose life all good Americans are proud then it would be equally proper to support or oppose a man because of his views on justification by faith, or the method of administering the sacrament, or the gospel of salvation by works. If you once enter on such a career there is absolutely no limit at which you can legitimately stop.
Theodore Roosevelt,
LETTER TO MR. J. C. MARTIN CONCERNING RELIGION AND POLITICS
November 6, 1908
http://www.theodore-roosevelt.com/images/research/txtspeeches/307.txt
Theodore "Teddy" Roosevelt ( October 27, 1858 – January 6, 1919) was the 26th President of the United States (1901–1909)
http://en.wikipedia.org/wiki/Theodore_Roosevelt
Matinecock Lodge No. 806, Oyster Bay, New York