God can be (and is) defined in ways that necessitate its existence. Such as "god is that which encompasses everything that exists" or "god is what encompasses all the stuff we don't know about" or "god is all the good stuff in the world" etc. The problem for the weak theist who attempts to give god a definition that makes it a rational entity is that 1. we don't have to call it god thus not a unique entity and 2. why should we care? A god that doesn't send us to hevean or hell or answer prayers or do magic tricks or anything else is pointless. Then the more specific the definition of god becomes the more irrational it becomes to believe in such a thing. The more irrational the belief system is the more irrational the behavior becomes. -- [plug in your favorite religious nutcase example here]
A mind is a terrible thing to waste -- don't pollute it with bullshit.