C-Span recently aired a debate in which Christopher Hitchens noted that “Religion… is the opium of the people” is not the full quote, and then he quoted it. Any body know it, or where it is located online. My googling has been failing me on this one.
See This site for the entire introduction.
It is found in the Introduction to his Critique of the Hegelian Philosophy of Right, 1844.
Here it is:
Religious suffering is, at one and the same time, the expression of real suffering and a protest against real suffering. Religion is the sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions. It is the opium of the people.
Hope that helps. In case you want to read the whole thing, here is the site:
http://www3.baylor.edu/~Scott_Moore/texts/Marx_Opium.html
That particular quote is the last sentence of the fourth paragraph
The minor differences in translation are interesting.
This might be it.
William S. Sahakian has accurately summarized Marx’s attitude toward religion:
Marxists reject religious doctrines about spiritual values, the soul, immortality, and God, asserting that religion is an illusion, and that the illusory happiness based on it must be condemned. “Religion is the sign of the oppressed creature, the heart of the heartless world, just as it is the spirit of a spiritless situation. It is the opium of the people”. God does not create man; rather, an creates invalid religion with its mythical God. Religion functions as a police force, as a bourgeois technique to dissuade the masses from revolting by promising them a better, happier existence after death than their exploiters allow them to enjoy during their lifetime on earth (William S. Sahakian, History of Philosophy, New York: Harper and Row, Publishers, 1968, p. 251).
As is often done with pithy remarks these are slightly recycled. Marx was paraphrasing Charles Kingsley in his **Letters to the Chartists[/] c. 1870:
We have used the bible as if it was a constable’s handbook - an opium-dose for keeping beasts of burden patient while they are being overloaded.
FWIW
MonkeyMensch: How did Marx writing in 1844 manage to paraphrase something written in 1870?
He used his time machine…duh. Actually, “Letters to the Chartists” was written in 1848, which is still too late.
::Wipes egg off face and slinks away::
What I meant to say, of course was:
As is often done with pithy remarks these were eventually recycled. Charles Kingsley, some years later, in his Letters to the Chartists wrote:
We have used the bible as if it was a constable’s handbook - an opium-dose for keeping beasts of burden patient while they are being overloaded.
I must have just mis-typed the original post. 
And here I thought opium was the religion of the people . . .
And for an untranslated version –
Full text (auf Deutsch) of the introduction here (The work itself is also there, on this page under 1843).
It’s nicer in the original. Thanks, panamajack.
A famed economist, whose name I can’t recall off hand, once submitted a paper to a journal. Because of his reputation, the article was not vetted to normal standards. When a letter writer noted that the solution in the paper wasn’t an optimum, but instead a pessimum, he replied with a letter stating that it was not an error, but an instructive lesson to the readers of the journal.
Where have I heard “…opiate (sp?) of the masses”?
All over the place. The only time I recall seeing it correctly, but abbreviated, was when I looked up in Bartlett’s. Unless you’re thinking of a specific incidence, in which case I haven’t a clue.
It’s just that I’ve heard “opiate of the masses” so much that “opium of the people” didn’t sound right.
Me too. Did you notice that when I double checked it in Bartlett’s I fixed the quote in the OP but forgot to do it in the title? Ha!