Richard Hitchens, author of god is not Great was recently interviewed at an atheist convention.  He says that Abraham Lincoln & Thomas Jefferson were atheists but I beg to differ as they often quoted God in a manner that accepts His existence.

"In regard to this Great Book, I have but to say, it is the best gift God has given to man. All the good the Savior gave to the world was communicated through this book." The Collected Works of Abraham Lincoln edited by Roy P. Basler, Volume VII, "Reply to Loyal Colored People of Baltimore upon Presentation of a Bible" (September 7, 1864), p. 542.

I tremble for my country when I reflect that God is just; that his justice cannot sleep forever. Thomas Jefferson

Once again, like his book, Hitchens' makes too many false generalizations.