Well that's refreshing!
If you say you can't prove there is a god, then I say you are agnostic.
Agnostics claim either that it is not possible to have absolute or certain knowledge of the existence or nonexistence of God or gods
From:
Agnosticism - Wikipedia, the free encyclopedia
As far as your evidence for the existence of a god, feel free to share. I have never seen/heard anything which has compelled me to believe, but perhaps you have new information.
Regarding having a dialogue with atheists/agnostics on how they arrived at their conclusion, did you read through the link I gave you earlier to the other thread about atheism? It explains a lot. Some people lost their faith, some people never found it, some people don't have it. I don't have it, that's how I arrived at my conclusion. When I hear about the concept of an all-knowing, all-powerful being, my brain instantly goes - "No way" My brain won't LET me believe. I'd have the same reaction if you told me if you concentrate hard enough you can make yourself disappear.
There are terms "weak atheist" and "strong atheist" which drive me nuts, and I avoid using them. It seems their definitions vary from site to site for one, but for two, it doesn't matter much. To me, they are essentially the same thing and one becomes one or the other depending on the conversation. There is also the term "apathetic atheism" which again, I think anyone who is an atheist can be depending on the time and conversation.
EDIT: That should say, "If you can't assert there is a god"