Over the years here, I have seen some GREAT religious discussions - and some that were not so great, lol! Although you are not likely to change somebody's mind if they are quite sure of what they believe, it IS very possible to help promote understanding of diverse opinions, and promote respect for that diversity. Those with very closely held opinions on the subject may find it difficult to understand why anyone could believe any differently than themselves, since it seems SO obvious to them. Maybe civil discourse can prove that it is reasonable for others to believe differently, and that we can agree to disagree.
For myself, I am open to proof either way, and I have not seen what I consider proof yet. I believe that if there is a God in the usual, omnipotent sense most believe in, then he/she/it would be a logical being. And that God would not have given humans the ability to use logic, but then demand that they believe in God by a leap of faith, without using that logic to question the faith. I believe that if there is a God of the type most believe in, then he/she/it will eventually reveal itself to me - now or later. But for now, I am still awaiting proof with an open mind. I guess that makes me agnostic.