O. Hobart Mowrer had one of the most productive and curious careers of any psychologist in the 20th century, despite struggling with severe mental illness and anxiety about his sexuality. Early in his career, he was one of the country’s leading experimental psychologists. During the mid-1940s, he became interested in religion and argued that anxiety was caused by repressed guilt that came from real wrongdoing. By the late 1950s, he had abandoned mainstream psychology, arguing that religion had been corrupted by its embrace of psychology and psychiatry. He claimed that sin was responsible for nearly all psychological problems and that ethical living and confession of wrongdoing could prevent mental illness. During his religious period, Mowrer received an astonishing amount of fawning press attention and was embraced by a public desirous of a path to mental health that did not require jettisoning traditional conceptions of sin, guilt, and human nature. This article examines Mowrer’s life and career and situates him among other mid-century skeptics of psychology and psychiatry. Other historians have argued that by the 1950s, the conflict between religion and psychiatry/psychology in the United States had largely abated, with both sides adapting to each other. Mowrer’s life and the reception of his work demonstrate that this narrative is overly simplistic; widespread conservative and religious distrust of psychology persisted even into the 1960s.