“It is the opium of the people.”
Marx was referring to religion and why it was necessary. Opium is a powerful narcotic and painkiller. According to him – and I agree with his analysis – religion to the vast majority of the people is a comforting illusion made a necessity by their real miseries. He wrote:
The abolition of religion as the illusory happiness of the people is the demand for their real happiness. To call on them to give up their illusions about their condition is to call on them …