Although the story takes place on earth, the phrase “war in heaven” describes the conflict between Michael the archangel and the devil in Revelations 12:7. The novel’s title points to Charles Williams’s recurring theme that the supernatural is always imminent in the physical world and can break through into ordinary life at any time. Williams stretches the boundaries of conventional realistic fiction to dramatize his belief that divine and demonic powers can become manifest in various ways on earth and interact with and through human beings.
Given this premise, even the most ordinary people can become agents of supernatural powers—whether good or evil. The archdeacon is a small, plump man who quietly sings hymns as he goes about his daily tasks, but it is through his prayer and submission to God’s will that the lives of Adrian and the duke are spared and the Grail ultimately restored. Gregory, who seems to be a typical retiree pursuing his hobbies, is responsible for a murder, for Barbara’s (temporary) psychic disintegration, and the nearly successful corruption of Adrian. Williams is less concerned with presenting his characters in their social interactions with one another than he is in presenting their cosmic dimension, their choices and interaction with the forces of good and evil.
Adapting the Arthurian Grail myth to a modern setting, Williams traces people’s reactions to the chalice as an indicator of their spiritual condition. The archdeacon views it as a symbol that represents but does not contain God’s presence in the world, so he has no desire for it and acts only in accordance with the guidance he receives in prayer. However, Gregory perceives it as a magical object that can be used to increase his power and is willing to harm others to obtain it. Unlike the archdeacon, Mornington sees it as an important Arthurian symbol, and the duke sees it as a sacred object of veneration, but both feel impelled to protect it from evil, a choice that leads to Mornington’s death.
Williams’s technique of intertwining the supernatural and the natural in a credible way reflects his belief that because of the Incarnation, the world has changed forever and is filled with God’s presence. With this novel, Williams affirms God’s providence, revealing his power and goodness and the ultimate impotence of evil.