An award-winning novel by Neil Gaiman, American Gods is a blend of both modern religions and ancient mythologies. This includes Norse mythology and Americana. Published in 2001 by British Publishing House Headline, this novel alludes to themes previously explored by Gaiman's The Sandman narrative.
The novel focuses on the idea that the existence of gods, goddesses, and other mythological creatures is dependent upon humanity's belief in them. Indeed, the gods are shown as a direct projection of the faith that produced them. Consequently, the strength of each divine being is derived from the strength of humanity's belief in them; without that belief, their powers begin to wane. The Old Gods particularly suffer from a lack of faith in the New World (i.e. America); their powers are greatly reduced compared to the New Gods (such as TV or Internet).
In the novel, Gaiman explores American identity and belief systems. Gaiman explores this theme by depicting Old World gods, or the gods who were brought to America, and the New World gods, or the gods who were created by Americans, at odds with one another.