John Adams was a Unitarian and couldn't be called a Christian. JQA definitely was. George Washington--no doubt about his beliefs, they are too well documented, including his personal prayers.
I think it is best and wisest to say that we are a Judeo-Christian Society. I would agree to that description.
I think so would the writer... He says that the Bible is what unites all the movements across time in the US...
Who are the great Jews in prominent American politics?
I don't understand the fascination with prefixing the correct term with the Jewish reference.
Quotes from John Adams
The general principles upon which the Fathers achieved independence were the general principles of Christianity
I will avow that I believed and now believe that those general principles of Christianity are as eternal and immutable as the existence and the attributes of God.
[June 28, 1813; Letter to Thomas Jefferson]
We recognize no Sovereign but God, and no King but Jesus!
[April 18, 1775, on the eve of the Revolutionary War after a British major ordered John Adams, John Hancock, and those with them to disperse in the name of George the Sovereign King of England." ]
[July 4th] ought to be commemorated as the day of deliverance by solemn acts of devotion to God Almighty.
[letter written to Abigail on the day the Declaration was approved by Congress]
"We have no government armed with power capable of contending with human passions unbridled by morality and religion. Avarice, ambition, revenge, or gallantry, would break the strongest cords of our Constitution as a whale goes through a net. Our Constitution was made only for a moral and religious people. It is wholly inadequate to the government of any other." --October 11, 1798
"I have examined all religions, as well as my narrow sphere, my straightened means, and my busy life, would allow; and the result is that the Bible is the best Book in the world. It contains more philosophy than all the libraries I have seen." December 25, 1813 letter to Thomas Jefferson
"Without Religion this World would be Something not fit to be mentioned in polite Company, I mean Hell." [John Adams to Thomas Jefferson, April 19, 1817]