This Present Darkness literalizes the battle between good and evil. The text affirms the reality of angels and demons as well as the existence of a spiritual realm that exists alongside and can interact with the physical world that human beings inhabit.

To drive the plot, Peretti writes the angels as though they were people with superpowers and the demons as though they were monsters and goblins from a fairy tale. This draws on biblical stories in which angels appear to interact with human beings, such as when the angel Gabriel appeared to Mary to foretell Jesus’s birth. In the novel, angels do not interact directly with humans, but the townspeople who are Christians can sense their presence. The angels themselves have an amalgam of human and supernatural abilities. While they appear like men, they are invisible to human beings, and they have capabilities of flight and can pass through any material substance. In the middle of a battle, for instance, Tal “vanished into the ground” (261) in order to escape, and there are countless instances of the angels flying all over the land.

The demons contrast with the angels since they share many qualities—invisibility, flight, the ability to move through objects—but they have one very obvious difference.