What a world that could be. Firat i pray that nothing like that ever takes place on this earth, we would truly be doomed. If i was to imagine 70% going down the drain, it's just like assuming the whole world has come to an abrupt end. That's a lot to loose. How do you even salvage anything? Wouldn't you want to save what is remaining so that you can rebuild from it? How do you start a new when there are no bases to build on. Once you destroy all the beliefs and religions that were there before, so what are you going to base life on, that simply means that life is going to be baseless, it will have no meaning really. Maybe it would make sense if you said all religions should be abolished with an exception of one where people will have no other religion to run to but the one that jas been availed, tbat would work but not all of them.