You know the problem with this subject is people are so sure of themselves. To say that you know for certain that something such as God does or does not exist is delusional in my opinion. And I'm not having a dig at having faith in any kind of religions here cos I think that can be a really good thing, if you do it for your own reasons and not for someone else's, but to be so certain of anything on this scale is quite delusional I think.