Oh, now this is just silly.Kopikatsu said:How do you convince someone that their belief in one God or another is wrong?
You can't. If someone is that dedicated to their belief, it's impossible to sway their opinion. It's best just to ignore them.
/Prepares flameshield
Of -course- you can convince someone that their god concepts are false; I'm living proof, and so are hundreds of millions of other ex-theists. This defeatist garbage is a waste of everyone's time.
As to the topic at hand: people believe different things for different reasons. People believe the holocaust is a hoax for different reasons. Before you try to convince them, get their perspective, and do your damnedest to determine both the root of their belief and, more importantly, any investment they might have in the belief. If they have some interest in trying to get people to deny the holocaust (say, Aryan Brothers trying to make Jews look like liars with a persecution complex in order to defame their character across the board and push them into the dregs), then the problem probably goes deeper than you can deal with.