Final answer:
The phrase 'Religion is the opium of the people' was coined by Karl Marx, who believed religion served to justify social inequalities and deter the working class from seeking improvements in their current living conditions.
Step-by-step explanation:
The phrase, "Religion is the opium of the people," can be credited to the German philosopher, journalist, and revolutionary socialist Karl Marx (1818-1883). Marx viewed religion as an ideology, a way of thinking designed to justify inequalities in power and status.
He argued that religion served to create an illusion of happiness among the working class, helping them cope with the difficulties of life under capitalism by orienting them toward the afterlife. This, according to Marx, discouraged them from seeking better economic or social conditions in their earthly lives. His criticism suggests that religion, by promising comfort and happiness in an afterlife, effectively prevents the working classes from challenging and changing their oppressed circumstances in the present.