A Bloody and Barbarous God investigates the relationship between gnosticism, a system of thought that argues that the cosmos is evil and that the human spirit must strive for liberation from manifest existence, and the perennial philosophy, a study of the highest common factor in all esoteric religions, and how these traditions have influenced the later novels of Cormac McCarthy, namely Blood Meridian , All the Pretty Horses , The Crossing , Cities of the Plain , No Country for Old Men , and The Road . Mundik argues that McCarthy continually strives to evolve an explanatory theodicy throughout his work and that his novels are, to a lesser or greater extent, concerned with the meaning of human existence in relation to the presence of evil and the nature of the divine.