It seems to be that most people think that a god exists or it doesn't. For most Christian's (apart from Don Cupitt, it's hard to know what he thinks even after reading his books) God definitely exists and is definitely good. But there are at least 3 possibilities to consider:
Most people who believe in a god don't seem to consider the fact that it could exist and could be evil. There is a 25% chance of that from the above diagram. "The above diagram is too crude!" you say. And I agree, there are more possibilities. For example it is possible that it sort of exists but is neither good nor evil, that would be the central square in the diagram below.
At this point the possibility that it exists and is good is reduces to (1/9)*100 = 16.7%.
"The above diagram is too crude!" you say. And I agree, there is an infinity of possibilities, as shown below.
God's existence and goodness could be on any point in the plane. Pushing it into a corner (bottom left) there is a god and it is good.
As to what sort of exists and sort of doesn't means, I leave that as an exercise for the reader. But (like quantum physics and personality and "the self" in Buddhism) existence and non-existence are not as clear cut cateogories that we'd like to think. (But see caveat at end of article)
And note that this is not a diagram about belief in a god or aethism, it simply shows the range of possibilities. The diagram for belief is another matter.
(Caveat: The Buddhist idea of a non-self is fine until you are at the dentists having a painful operation. Then you know who is feeling the pain, yourself. Sure as hell there is a self then.)