"...the heart of the heartless world, the sigh of the oppressed creature, the spirit of the spiritless situation; the opiate of the people. Criticism has plucked the flowers from the chain, not so that men may wear the chain without consolation, but so that he may break the chain, and cull the living flower." - Paraphrased by Hitch.
We have all heard the vulgarized or unrefined form of the above quote. It starts and ends with "Religion is the opium of the people", or something very similar. It should be noted that this is not what Marx really expresses here. I thought it worthy to post the quote in it's entirety, in order to give more context - but more importantly - to provide extra content, to what Marx actually said about Religion. In this verse he expresses something more profound and eternal than the neutered, watered down version it has devolved into since the original words were written. Marx was the author of more than just influential books and routinely quoted phrases (which now are reduced to soundbites), his works radically and profoundly changed the course of history and the reverberations, although diminishing, are still vibrating to this day. Words do change the world and this is an irreproachable example of the proverb "the pen can be mightier than the sword' - Karl Marx's novels and slogans became far more powerful than anyone could have predicted at the time.
"Religious distress is at the same time the expression of real distress and the protest against real distress. Religion is the sigh of the oppressed creature, the heart of a heartless world, just as it is the spirit of a spiritless situation. It is the opium of the people. The abolition of religion as the illusory happiness of the people is required for their real happiness. The demand to give up the illusion about its condition is the demand to give up a condition which needs illusions."
-k.marx-"Critique of Hegel’s Philosophy of Right".
Thanks, Brady. 3fs.org