Starting in the 1940s, the US Supreme Court began turning America into a secular nation under their "separation of church and state" doctrine - - an out-of-context phrase that was derived from a private letter written by Thomas Jefferson.
Apparently, neither Jefferson nor George Washington got the Court's memo. Here is a small sampling I ran across this weekend while reading a compilation of some of their famous orations in Alexander K. McClure's "Famous American Statesmen and Orators" (1902):
"And can the liberties of a nation be thought secure when we have removed their only firm basis, a conviction in the minds of the people that these liberties are of the gift of God? That they are not to be violated but with His wrath? Indeed I tremble for my country when I reflect that God is just: that His justice cannot sleep forever." Thomas Jefferson, Notes on the State of Virginia, 1785.
"It would be peculiarly improper to omit, in this first official act, my fervent supplications to that Almighty being, who rules over the universe, who presides in the councils of nations, and whose providential aids can supply every human defect, that His benediction may consecrate to the liberties and happiness of the people of the United States[.]" George Washington, First Inaugural Address, April 30, 1789.
"We ought to be persuaded that the propitious smiles of Heaven can never be expected on a nation that disregards the eternal rules of order and what which Heaven itself has ordained." George Washington, First Inaugural Address, April 30, 1789.
"Before taking my leave on this occasion, [I appeal] once more to the benign Parent of the human race, in humble supplication, that, since He has been pleased to favor the American people with opportunities for deliberating in perfect tranquility, and dispositions for deciding with unparalleled unanimity on a form of government for the security of their union and the advancement of their happiness, so His divine blessing may be equally conspicuous in the enlarged views, the temperate consultations, and the wise measures on which the success of this government must depend." George Washington, First Inaugural Address, April 30, 1789.
"Of all the dispositions and habits which lead to political prosperity, religion and morality are indispensable supports. In vain would that man claim the tribute of patriotism, who should labor to subvert these great pillars of human happiness, these firmest props of the duties of men and citizens.… Let is simply be asked: where is the security for property, for reputation, for life, if the sense of religious obligations deserved the oath which are the instruments of investigation in courts of justice? And let us with caution indulge the supposition that morality can be maintained without religion. Whatever may be conceded to the influence of refined education on minds of peculiar structure, reason and experience both forbid us to expect that national morality can prevail in exclusion of religious principle…. It is substantially true that virtue and morality are a necessary spring of popular government. The rule, indeed, extends with more or less force to every species of free government. Who that is a sincere friend to it can look with indifference upon attempts to shake the foundation of the fabric?" George Washington, Farewell Address, September 19, 1796.
I could go on, but you get the point.