Holy War

One idea many mythologies include is the power of faith: deities need followers because they give the god power. This is often used as an excuse to justify why gods bother with temples, mortal followers, and things like clerics. This idea never seems to mesh well with the concept of evil gods. It can be explained if the dark gods have a portfolio that includes something best avoided – such as sacrifices to a death god to help an injured family member pull through or an offering to the goddess of monsters to avoid predators on a long journey. However, there is unlikely to be casual worshippers of a god of assassins or infanticide. If a god is really only worshipped by a cult of a dozen people, how do they remain a god?