I am certain in my belief that organised religion is nonsense and man made. The element of doubt is in reference to another question, it comes from not knowing answers to something, like many things that cannot be explained in science or scientific terms. Religion gains strength from this, only belief survives when this doubt is removed, which is why it interests me.
If, in the unlikely scenario in the near future we discover a theoretical force that created all matter, then religion would consider this as a proof of god, I'd consider it a proof in science.