Reality, belief, and evidence.

Reality is that which, when you stop believing in it, doesn't go away. When you believe that elves cause it to rain, each time it rains, you'll see evidence of elves. If you believe that rain is caused by condensation of water vapor in rain clouds, each time it rains, you'll see evidence of condensation of water vapor in rain clouds. The thing is, when you stop believing in elves, you'll stop seeing evidence of elves. And when you stop believing in condensation of water vapor in rain clouds, you will still see condensation of water vapor in rain clouds.

That is why belief as a prerequisite of seeing evidence for something is obviously suspect.