John Piper gave an analogy once (here, a couple paragraphs down under "A Holy Fear"), in which he likened the fear of God, for a believer, to being caught in the middle of a raging snow storm while hiking a glacier. The storm is terrifying to behold, but being a believer is like being safe inside a cleft of a rock, safe and protected from the storm raging just feet away. The storm is still terrifying, and to step outside the safety of the cleft would be certain death. Yet, you are safe inside, much like being safe in Christ. "Perfect love casts out fear", in other words, doesn't reject that the storm is still a storm. It's just that you are safe and no longer fear it in that way.
This video might be another apt illustration.
He says "I trust the conservation of energy 100%." He trusts his understanding of the laws of physics, in other words. And he proves it, as you can enjoy watching for yourself (!).
He does prove his trust in those laws. Yes indeed. But...not without fear. :)