Pure arrogance.

If you have any Christian experiences, any member of that ever growing phalanx of aggressive atheists will 'destroy' you if you have the temerity to voice them.
Ad hominem arguments will abound.
There are two lines of attack: firstly you have misinterpreted what happened {probably due to some kind of mental incapacity} OR secondly you are a liar! {No doubt. No questions. Whatever you say happened - DIDN'T!}

This new breed of aggressive atheists are seriously unpleasant people. Isn't it strange? - Whenever I meet an atheist who is not of the left - they will treat you as a human being, an equal and will possibly even debate with you.
When that atheist comes from the left - you can often FEEL the hatred, not only of your beliefs but of you for having them. {Unless you are muslim, of course, when all bets are off.}
Seriously, test me on this one!