"It is by teaching a slave the duties of religion that he will learn his duty towards his master"

Quoted from "A History of the Island of St. Helena”, by T. H. Brooke, Esq., published in 1824, page 406 (available through Google Books).

From this we are reminded that religion has always been used by the leaders of society to control the 'lower classes'.  "Never mind that your life is hard", they are told "you will be rewarded in Heaven".  What better excuse for not dealing with the social issues of the day: poverty, health, etc.?

Karl Marx described religion as the "opiate of the people", by which he meant that it calmed them down and prevented them from rising up and overthrowing their oppressors.  I agree with his analysis (though not with his proposed solution - communism).