What would be wrong if I can't get it started while having spark and gas flow?

Did you check fuel pressure? Clogged fuel filter will do that. Of course, so would a clogged catalytic converter. That is of course if you did not blow up the motor (which also sounds like a possibility). Did the engine make any noise before it stopped running.

Like michael said, check fuel pressure. Next guess is maybe you snapped or slipped a timing chain. If it has snapped the spark plugs shouldnt fire becasie the cam and distributor wouldnt rotate. If it slipped they will spark but not at the right time. Take a timing light and see if ingintion timing is spot on or way out.