“I believe in one God, and no more; and I hope for happiness beyond this life. I believe the equality of man, and I believe that religious duties consist in doing justice, loving mercy, and endeavouring to make our fellow creatures happy.”

The God-Seeker (1949), Ch. 57

Source: Faithless

Source: Postcards from Ed: Dispatches and Salvos from an American Iconoclast

Unidentified ‘member’ of MySpace.com circa 2007–08, quoted in Richard Kennedy The Disgrace of MySpace (self-published [Lulu.com] 23 August 2008, ISBN 9781435760042, page 123. This passage and slight variants of it have been widely attributed to Audrey Hepburn long after her death (for example, in Glamour March 2012, page 78); but no evidence of its existence has been found during Hepburn’s lifetime, attributed to Hepburn or anyone else. It has not been found in print before 2008.
Misattributed

Quoted from Larry King Weekend, Interview With Maharishi Mahesh Yogi (2002-05-12) http://transcripts.cnn.com/TRANSCRIPTS/0205/12/lklw.00.html

"Articles of Belief and Acts of Religion" (1728).
1720s

1850s, The Present Aspect of the Slavery Question (1859)
Context: Such is the present aspect of the slavery question. For myself, I believe that the faith in which the government was founded still survives. I believe that the spirit of despotism which now says to the country, 'I will rule or ruin', will hear the imperial voice of the conscience of the American people, recognizing that justice and prosperity walk hand in hand, saying, 'You will do neither'. I believe that God did not hide this continent through all time as the spot whereon a nation should be planted upon the only principle that can render a nation as permanent as the race, to suffer the experiment to fail within a century. I believe these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain inalienable rights, that among these are life, liberty, and the pursuit of happiness. Do you believe it? If aye, let us go into the battle, and God speed the right.

Responding to audience questions during a speech in Detroit (1898); as recounted in Living My Life (1931), p. 207; quoted by Annie Laurie Gaylor in Women Without Superstition, p. 382
Context: Ladies and gentlemen, I came here to avoid as much as possible treading on your corns. I had intended to deal only with the basic issue of economics that dictates our lives from the cradle to the grave, regardless of our religion or moral beliefs. I see now that it was a mistake. If one enters a battle, he cannot be squeamish about a few corns. Here, then, are my answers: I do not believe in God, because I believe in man. Whatever his mistakes, man has for thousands of years past been working to undo the botched job your God has made.
As to killing rulers, it depends entirely on the position of the ruler. If it is the Russian Czar, I most certainly believe in dispatching him to where he belongs. If the ruler is as ineffectual as an American President, it is hardly worth the effort. There are, however, some potentates I would kill by any and all means at my disposal. They are Ignorance, Superstition, and Bigotry — the most sinister and tyrannical rulers on earth. As for the gentleman who asked if free love would not build more houses of prostitution, my answer is: They will all be empty if the men of the future look like him.