Mary Mallon survived typhus when she was young. She did not show any symptoms from the disease, but carried its bacteria in her body. Mary was a kindly person, but the problem was, she was also a cook. Over the course of her life fifty-three people may have died as a result of exposure to the deadly disease. Throughout her life, Mary piously denied any connection between her cooking and those deaths.

Bad religion also kills. The violent history of religion should call us all to a ruthless examination of our core ideas. Sometime back, a local seminary celebrated John Calvin’s 500th birthday by dedicating their monthly magazine to him. One of the articles wished to dispel negative beliefs about John Calvin, for example, the belief that he was sadistic. Calvin played a big role in the execution of the Unitarian Servetus. The article said, “Calvin argued that Servetus should not be burned at the stake. The conventional picture of Calvin cruelly twirling his moustache like Snidely Whiplash while Servetus burned is baseless. Calvin urged the courts to spare Servetus from burning, which Calvin considered a barbarous method of execution and to behead Servetus instead.”

I’m sure the author is a wonderful person, but it was disconcerting to see a kind person defend a beheading because it was kinder than burning the victim. It is not enough to cherry pick out the poisonous parts of a religion and pass off the rest as harmless. A good tree should not produce poisonous fruit in the first place. Even if we pick off the poisonous parts, they will grow back as sure as Typhoid Mary.

We are all born into worldviews that have traces of prejudice, superstition or sectarianism. We must treat these traits like we would an infectious disease. Religion that does not regularly exorcise those demons may want to be kind, but it carries within itself the disease it would seek to cure.