One of the problems with discussions between believers and non-believers is that both groups of people claim to have knowledge about the subject rather than merely belief. The Christian might think "I don't just believe in God, I know that he is there" while the non-believer probably thinks "I know there is no god".
The problem with these mindsets is that there is no room for dialogue. They can't possibly both be right.
I am of the opinion that it is possible to know God, but you know the person, but believe things about him. Over the years my beliefs about God have changed. Hopefully they're getting closer to the truth, but that might not be the case. Either way, if there is room for change, then I don't actually have definitive knowledge about God.
I used to think that I was right to talk about what I know about God, while I shunned the 'belief' word. But the more I think about it, the more I see the arrogance of that position and am more inclined towards belief. If you merely believe something, you acknowledge that you have more to learn, if you claim to know, then the door to learning is shut.
Also, if you merely believe things, the road to dialogue is open. Not merely dialogue with non-believers, but dialogue with other believers in different traditions. If you merely believe things, you can agree to differ on many things, but if you know you are right, then you probably know the other is wrong, and the common ground between you can get very thorny.
Remember Paul's words (1 Cor 13:8-12) "... where there are prophecies, they will cease; where there are tongues, they will be stilled; where there is knowledge, it will pass away. For we know in part and we prophesy in part, but when perfection comes, the imperfect disappears. When I was a child, I talked like a child, I thought like a child, I reasoned like a child. When I became a man, I put childish ways behind me. Now we see but a poor reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known."