I was wondering if such an event would have any effect on atheists/ agnostics? Would such an event make a non-believer re-think his/hers position? Are all atheists going to their graves as stanch atheists or would there be doubters? If there's doubters, which religion would make more sense to them to join? What does Islam say about catastrophic events and of the world scenarios?
Simple answer? All atheists will stay atheists, and if their was doubters, they wouldnt really have time to think about what religion makes sense, and since most have come to the conclusion none make sense, there probably wont be too many that decide to suddenly believe in a god that cant save them. Also what would be the point? As far as im aware not believing in god is a sure way to go to hell according to any religion, and since thats already happened believing wouldnt change their fate.
I think in fact its more likely that those that believe in a god that is supposed to protect and save them will convert to atheism if faced with certain death(and we all face it eventually), it would seem their life was a lie and anything they couldnt do according to their religion they'd regret not doing.