Two women from the latter (a mother and daughter) both discuss who they were taught to beat their children, and they did so out of a belief that they had to assure their and their children's places in heaven.

That is what happens when your foundational figure is best known for torture/execution.

To be fair, Mortification of the Flesh also happens in strands of Hinduism, Buddhism and Shia Islam. All which include founders' tortures or martyrdoms. Christianity is only exceptional in that all of it and not just some sectors of it are subject to the same initial conditionals.