So

1. (x) : x is a possible entity. the more complicated x is the less likely it is to exist controlling for other evidence.

2. (x): x is a possible entity. the more intelligent x the more complicated x is, controlling for other properties.

3. God is maximally intelligent.

:. God's existence is maximally unlikely unless there is other evidence or unless it has other properties that make its existence maximally more likely.

(Assume intelligent to refer to the possession of general intelligence)

I think most theists will consent to (1), especially given that its implicit in some of their favorite arguments. (3) They consent to, unless they mean "God" as merely a cosmological constant, or first cause. In which case we're having a completely different debate. So the issue is (2). I'm sure some of the cognitive science types can give evidence for why intelligence is necessarily complicated. There is however, definitive evidence for the correlation of intelligence and complexity. Human brains are vastly more complex than the brains of other animals. Computers get more complicated the more information they hold, etc. It might actually be worth making the distinction, between intelligence and the holding of data. It is a lot easier to see how the more information something contains the more complicated something is since one can just compare two sets of data, one bigger than the other, and see that one is more complicated. Presumably, God needs to contain information on everyone's behavior, the the events that happen at any point in time, prayer requests etc.

Btw, is there a way for me to us symbolic logic notation in xml?