Why logic and reason fail when we try to trace back the origin of universe!!! When we try to think what might have created the universe,when was it created,how,why,where etc etc, the parameters we are looking at are TIME when we say WHEN and SPACE when we say WHERE,HOW,WHAT,WHO. Out of the ten or so dimensions that were created simutaneously space and time constitute four.That is why we cannot imagine of anything before the big bang because there was no time before the bigbang.Time itself was created at the moment of bigbang.We fail to imagine or guess what existed before bigbang because we imagine things in terms of matter or energy.both of them did not exist before bigbang. So,to conclude : We do not know what existed before bigbang simply because we have not come across anything like it ,as of yet. so,keep looking and dont simply say it was the hand of GOD!!!