Do you have to call religous belief 'fairytales'? That is very offensive. Who are you to say that God doesn't exist? How do you know? I respect your right to believe their is no God. And I agree with you that religous belief should not used a basis for making laws. But please respect other peoples' right to believe in God. You don't have to demean people just because you disagree with their religous beliefs. Be careful that your beliefs do make you intollerent of others.
One last thing: trying to prove or disprove the existents of god is pointless. It can't be done one way or the other.