This is quite easy to answer really, its documented fact (film, pictures, people still alive that witnessed it) that the holocaust took place.
Yet in history of all time, there is not one shred of evidence that god exists, nothing, as far as I can tell (which id wager is nearly about right), is that god was made up by human beings to make themselves feel better about not dying and to try and instil into people morals etc etc as society became more advanced + complex.
Then different societys sprung up and wanted to change there ways slightly, thus they made a 'new' god etc etc etc (hence many religions formed), hence another reason why all religiious scripts read 'only obey our god, kill everyone else who doesnt believe'
I can go on for hours but, the point is, a rational person can weigh up the pros/cons etc and see that theres no evidence for god exisiting, but overwelming evidence pointing towards that humans made the idea of god up......we even wrote the books that supposdly the man upstairs wrote, everything a religious person can say about the ways of there religion can easly be disproved
Then you get those sorts, well prove god doesnt exist....... well we have good ideas about how the universe came to be (big bang etc etc), far from knowing for sure, but id imagine were going along the right track...at least were on a track...its a damn sight more reasonable than saying, 'oh it came to be, because it is so'
Most religions make me giggle in which they 100% beleive the earth was created 5000 years ago
................the trouble is with the human mind tho, you can present the evidence point blank in there face, Irrefutable evidence such as carbon dating and genetic markers, even if one was to say 'its not for sure this is correct' its HIGHLY likely that it is true though, yet they will just go '''''urrrrrrrrr ** no, its not true because my book some bloke wrote donkeys ago says it isnt', surly thats a sign of madness? or they use the, 'oh god planted that evidence there to try and see if you beleive in him or not' again i beleive the medical term for this is something like below:
Delusional
PSYCHOLOGY false belief: a persistent false belief held in the face of strong contradictory evidence, especially as a symptom of psychiatric disorder
Does it not concern anyone else that most of the world is off there rockers?
EDIT:sorry to swing the debate back to religion, but its always a good debate to have