God

A god is generally an individual that has transcended the material plane and become the beacon of a groups faith in ideology. Divine power comes the will of a large population believing in a god, and even if that god does not exist.

Creating a God

Gods are generally created by a cult of personality or a strong leader. Once enough people truly believe that their leader is actually their god it may actually cause the leader to start generating divine power. Once a faithful population forms it is nearly impossible to kill an ascended individual so long as there are some people who believe in that god still.

Killing a God

Gods are not immortal but incredibly powerful beings. They have the ability to shape reality and the planes of existence and commonly create their own planes of existence for their followers souls to reside after death. Because a god generally creates their own plane for the souls of their followers even if you where to kill every follower of a god their souls that exist still know of the god and will keep its divine power alive.

At the moment of death of a god their soul attaches itself to the soul of the most compatible living being that it can find. Compatibility has been historically noted by how similar they are personality wise to the original mortal form of the god, or how ideologically aligned with the core beliefs of the god.