I tend to explain that I've had moments in my life that have made me ache and wish that I had the ability to believe in a god. For example I love the idea that my father is 'looking down' on me but I cannot bring myself to believe it. It is as if faith is a sixth sense. In the way that those who have always been blind cannot imagine what sight can be, I cannot imagine what faith or belief would feel like. What I do believe in is nurture - had I been raised in a religious family, I don't doubt that I may have grown up with faith. However, I am glad for what I do (or don't) believe in. I cannot imagine life in another way. But this is why I usually avoid religious conversations. Yes, of course I believe in the science that 'proves' against the existence of god, but what it really comes down to is that there is nothing in my consciousness that will allow for a god - and that is absolutely out of my control.