It’s a fact that nobody knows why Karl Marx turned away from God. It’s never been revealed what turned him from a defender of the faith to a person who would climb to Heaven if he could kill God.
I read a book on the guy once. According to the book, he was a complete loser in life. Always broke, dirty, free-loader. Pretty much a dirty, smelly hippie of the 1800’s with a European flavor.
I could see a loser like that blaming God, corporations, and successful free market types as the cause of his misery.
Read “Between Marx and Satan” by Richard Wurmbrand.