The workers may secure a greater or lesser degree of political liberty to fight for their economic emancipation, but no amount of liberty will rid them of poverty, unemployment, and oppression until the power of capital is overthrown. Religion is one of the forms of spiritual oppression which everywhere weighs down heavily upon the masses of the people, over burdened by their perpetual work for others, by want and isolation. Impotence of the exploited classes in their struggle against the exploiters just as inevitably gives rise to the belief in a better life after death as impotence of the savage in his battle with nature gives rise to belief in gods, devils, miracles, and the like. Those who toil and live in want all their lives are taught by religion to be submissive and patient while here on earth, and to take comfort in the hope of a heavenly reward. But those who live by the labor of others are taught by religion to practice charity while on earth, thus offering them a very cheap way of justifying their entire existence as exploiters and selling them at a moderate price tickets to well-being in heaven.
Religion is opium for the people.
Religion is a sort of spiritual booze, in which the slaves of capital drown their human image, their demand for a life more or less worthy of man. But a slave who has become conscious of his slavery and has risen to struggle for his emancipation has already half ceased to be a slave. The proletariat of today takes the side of socialism, which enlists science in the battle against the fog of religion, and frees the workers from their belief in life after death by welding them together to fight in the present for a better life on earth. Religion must be declared a private affair. In these words socialists usually express their attitude towards religion.