I've answered the question before, in response to PZ, but I'd like to add a little more after Jerry Coyne asks: Why are you an atheist? Does it have anything to do with a lack of evidence for god, or are there other factors involved?
PZ's contention is that there can be no evidence for a god, period. Jerry argues, that, whilst none has been presented, it could be possible. This initial discussion led me to state "There is no god".
I side more with PZ, but I'm not going to stick my neck out and say there could *never* be any evidence for God. I strongly suspect this to be the case, but, my limited imagination could be at fault.
However, for there to be evidence for god, we do need to define what a god is, and what it does, and evidence for this. I strongly suspect that this will never happen. I'm almost absolutely certain this is so, but, and for all intents and purposes, you can remove that "almost". For me to be proved wrong will require a theist to get a coherant hypothesis, and, given the time that's been available, I can't see this happening.
So far, there aren't any decent arguments that I've seen. "Sophisticated" theology or not.