Final answer:
The secularization thesis is a sociological theory that suggests the decline of religion in modern societies as they become more advanced. Sociologists such as Durkheim, Weber, and Marx believed that modernization would lead to a decrease in the importance of religion.
Step-by-step explanation:
The secularization thesis is a sociological theory that suggests the decline of religion in modern societies. It posits that as societies become more modern and technologically advanced, the influence of religion diminishes.
This theory was discussed by sociologists such as Émile Durkheim, Max Weber, and Karl Marx, who believed that modernization would lead to a decrease in the importance of religion.