The answer is: He felt religion was against revolutionary ideals.
Karl Marx viewed religion as a tool used by the ruling classes to maintain control over the working class. He believed that religion provided an illusion of happiness and contentment, which distracted people from the realities of their exploitation and oppression. This perspective is encapsulated in his famous quote, "Religion is the opium of the people." Marx argued that religion was a barrier to revolutionary change because it encouraged people to accept their suffering in the hope of a better afterlife, rather than seeking to change their material conditions in the present.
While Marx did believe that religion played a role in maintaining the status quo, his primary concern was not that it directly prevented financial success, but rather that it perpetuated a system of exploitation. His focus was more on the structural and systemic issues of capitalism rather than individual financial success.
Marx did discuss the concept of alienation, but it was more directly related to the capitalist system and the nature of labor under capitalism. While religion might contribute to alienation by providing false consciousness, Marx's primary critique was that religion masked the true source of alienation, which was the capitalist system itself.
Marx's critique of religion was not centered on the idea of individual life control. Instead, he saw religion as a collective social phenomenon that served to uphold existing power structures and prevent collective action for social change.