Gregory taught that while suffering in general is caused by human sin, that does not mean particular forms of suffering are always the result of specific sins. He warned against making too direct a connection between sin and suffering, since that, after all, is one of the main lessons of the book of Job. In Moralia, Gregory shows that Job’s friends insisted that his great suffering had to be punishment for some equally great wickedness. But they failed to see that suffering in the world is of many different kinds and serves “a number of purposes in the divine economy.”