In our universe the further back in time the more powerful the event is - so in order for something to be all powerful (eg. GOD) it would have to be the first event - the initial particle / force - but inorder for an event to occur would there not have to be two factors... (unGOD? haha) This is all based on the fact that there are universal rules and everything must obey. So all events till now can be mapped back to that first event. The configuration of those particles has determined everything from then on. If this was the case the only place an influencial action could have been made would have been right at the start - from then on power to alter things has been rapidly deminishing as things get more and more complex. So even if there was an all powerful force its out of its hands now.
So if there was a god, their power is rapidly diminishing...