What is the theme in Saint Maybe by Anne Tyler?

Guilt is a theme of the novel. Ian Bedloe feels guilty for telling his brother Danny that his wife is cheating on him. This guilt leads him to leave college and raise Danny and Lucy’s children. He gives up on his former life and loses his girlfriend because of the guilt he feels. When he discovers that Lucy was not cheating on his brother, he feels even more guilt. This guilt eats away at him and makes him question himself and his actions. It also makes him jaded to the actions of others.