There are always aspects of violence, God, and humor in O'Connor's works.
God and religion is present in her works and used to convey that humans are selfish in their actions instead of seeing opportunities to show love or compassion unless something traumatic occurs that makes them come to this realization. O'Connor generally uses a negative experience to drive the lesson home.
Violence and cruelty are another type of them that can be found in O'Connor's work. She creates a situation in which it takes a violent experience to get the character to realize their mistakes and find God. O'Connor believes that the use of violence is a necessary aspect in order to get the reader's attention.
Although it might not seem so at first glance, O’Connor is a Christian writer whose stories contain a message, usually about our need for humility and understanding. She often depicts her characters as somewhat grotesque—having a very bizarre feature in some way—and lacking understanding concerning their moral situation. This grotesqueness symbolizes their and our moral flaws. Stories resolves themselves often through gained insight, frequently brought about by violence. Please follow the link to enotes discussion on O'Connor for fuller information.