... in the vein of this.
Jesus says in Mark 11:23 I tell you the truth. Anyone may say to this hill, "Go and jump into the sea." He must not doubt in his heart, but he must believe that he will have the things he asks for and he will have them.
What if Jesus didn't mean "if you have faith, I will move the hill (mountain) for you", but "if you have faith, the hill will move because the Universe was built to respond to human volition"? We know that the human body responds to human will sometimes (placebo effect); there's a speculative part of physics (quantum physics) that has as a basic tenet that human observation can influence the outcome of physical processes.
Why the need for "unwavering" faith, then? Well, the Universe is probably a simple mechanism, if you're not very sure of what you want it cannot respond to your will. Maybe there's a "faith threshold" that triggers the mechanism; or maybe there's a required ratio between the "amount" of faith and the desired effect (so less faith would be required for moving a pin than for moving a mountain).
As I said - speculation; it's not something I actually believe, for now it's just an amusing idea.