@ReedS,
Quote:"Why do people believe in god"
The phrasing of the question can refer to an individual or group of individuals. I'll give my answer for both.
Referring to people as individuals, it is because they are raised by others who believe in god, and are encouraged by religions to faithfully believe rather than question that belief.
Referring to people as a society, a belief in god gives comfort and reason when faced with fear of the unknown or uncertainty and is encouraged by religions in order to govern their followers.