I am commonly asked if I believe in relativity, or if I believe in evolution.
I answer, no. I say I don't believe in anything, but I do trust that they are right. Or, I say that as a scientist, it's more a matter of my drawing fact-based or evidence-based conclusion. Awkward, but there you go.
But Sean at Cosmic Variance also tackled this matter, and does so very well, with excellent examples of proof versus belief. We can't prove anything to be true in science, but sometimes, you know, it's the way to bet. If I hold a rock over my toe and let go, I can pray all I want, but in the end gravity wins.