You don't. They have a right to their zealotry as you have a right to your beliefs. I also don't get why you want to reason with crazy? You must be very young

You don't. They have a right to their zealotry as you have a right to your beliefs. I also don't get why you want to reason with crazy? You must be very young and ideological or enjoy arguments. As you get older you realise the best way forward is to leave people to their beliefs as long as they don't impede yours. If they _are_ impeding your beliefs then you have a problem -- either avoid the conflict or stand your ground -- it has to be done on a case-by-case basis though, there's no blanket answer.