[dcarson]

Harry Turtledove has a semi series,

Between the Rivers is set early bronze age when the god of the cities between the Tigris-Euphrates rivers are starting to lose their focus on what people are doing and in some cities you can do what you want instead of what the god wants as long as you don't get too obvious.

Thessalonica where the old gods have been forced into the very rural areas in early Christian Greece.

The Case of the Toxic Spell Dump set modern times where for example an investigator is impressed with a hermetically sealed lab because maintaining a artificial cult to Hermes is expensive.