To answer the original question, i dont think it is so much to do with proving whether god does exist or doesnt exist, whether religion is right , or science is right, or atheism etc.
I think what most people are asking of the religious ones, is to please justify why you believe in something that doesnt exist in a physical form, and that the belief in a higher metaphysical being or deity is not grounded in logic or on any factual basis.
I think people like to debate the reasoning behind ideas, the thought's or convictions that led them to make the decisions to believe in the things they do, but what is puzzling i think to many, is the utter belief that many of the religious people portray, in the fact that they are correct and everybody else is wrong, and that they are not very open-minded about the possibility even remotely that there may be more to life other than what they have been told by their spiritual leaders
Most of us at some point make a choice as to what we wish to believe, but many religious people are brought up in households, communities and societies that have ingrained belief systems, that they themselves take on or follow through tradition, peer pressure, family pressure or pressure from the community.
Those of us who grew up with the right to choose our beliefs find it hard and down right difficult to comprehend how intelligent thinking individuals can simply just accept something as it is, without having explored, read or investigated anything else. Some do ,and some return to their original point , but at least then it is from an informed decision, and is of their own choosing.
Proving or disproving the existence of God is not the point , the discussions, debates and arguments are what is enjoyed, how else do we learn?, how else do we gather information? and how else can we put our ideas or beliefs across to other people.