People believe in God because the concept of such a being has introduced to them.
This is demonstrated by the fact that if you introduce a divine persona (a god or other celestial creature) from one particular culture to an individual from another culture where that particular divine persona does not exist, that individual will not be familiar with it, and may not even believe in it, even if it is explained to them.
So, for example, if you tell a person who is from, for example, a Christian background about, that a chair spirit lives in your furniture, the Christian would wonder, "why would anybody think furniture has a spirit?" Because such a funny idea had never been introduced to them before. But the Christian hads no problem believing in a God, because that is an idea, a very concept, that has been previously introduced to them, and so they believe it.
Likewise, if you grow up never being told of the concept of a "god" then there is no reason why such an absurd concept should ever occur in your imagination, except as a magnification of the ego.
The concept of a god is absolute. And since it is a personification, it has the curious quality of bringing out in people both extreme humility and extreme ego inflation. So, this belief can have some very good effects or it can have some very bad effects.
However, both extremes depend totally on the assumption that a 'self' inherently exists, and this is a notion which is the opposite of that which forms the basis of the dharma, for the actions, expressions and qualities of a god can only be reckoned in the context of, in contrast with and in comparison to, a 'self' (atma, soul, etc.).
When it is demonstrated that there is no self, then nothing has been created, hence no creator. No 'self' is born or dies, no 'self' experiences the omnipotence of a god.
When the self isn't there, a god isn't there either.
There is a lot that god cannot do. God can't go anywhere. god can't know the joy of being pleasantly surprised. God can't acquire a new skill or learn from mistakes. And God cannot act logically or illogically, since doing either one would deny the other, and that would be an incomplete.
Profile Picture: "The Foaming Monk"
The Chinese characters are Fo (buddha) and Ming (bright). The image is of a student of Buddhism, who, imagining himself to be a monk, and not understanding the true meaning of the words takes the sound of the words literally. Likewise, People on web forums sometime seem to be foaming at the mouth. Original painting by P.Volker /used by permission.