The movie Agora shows a Christian fire-walking as a miracle proving faith. Arthur C. Clarke made a TV documentary on the subject offering a host of natural, scientific explanations. I just cited a Straight Dope post on the subject (within my own Agora series, linked just above).
I quote the SD comments:
Jearl Walker, the former Scientific American columnist and, it turns out, the G. Gordon Liddy of physics … also dips his bare hand in water and then plunges it momentarily into a vat of molten lead, 700 degrees Celsius. Says Jearl, who’s even done this on Johnny Carson, “there is no classroom demonstration so riveting as one in which the teacher may die.”
Moses turned a staff into a snake before the priests of Pharaoh. Agora‘s Amonius walks on fire: like Pharaoh’s priests, his would-be converts mistake the “trick” for a miracle. It’s good theater: but does a trick prove anything? Other than audience ignorance? gullibility? whichever of the above three kinds of trick it is: a mechanical trick (like a trick deck), slight-of-hand, audience ignorance (people can be relied on not to know physics, chemistry …)
I myself have been impressed by pedagogical theater. In college, at Columbia, my freshman physic professor, Arron Sachs, showed his faith in physics, specifically in the law of conservation of momentum, when he suspended a wrecking ball on a chain hung from a swivel in the center of the large lecture hall’s ceiling. Sachs tugged the wrecking ball along with him as he climbed to the utmost corner of the hall. He held the ball touching his jaw. His head couldn’t go back another millimeter. He smiled at us. He released the wrecking ball: a huge damn piece of iron, several hundred pounds of mass. The ball swung away, traveled the cross section of the hall: extreme NW say to extreme SE. Then, as a pendulum, it began the return trip. The ball swung back toward Professor Sachs. Sachs remained perfectly still, smiling at us. The ball reached his corner and kissed him gently on his cheek before swing away once again.
The point was. The ball could swing back to its starting point, but not behond it: not without additional impetus beging added. No student flew to the ball and gave it another shove. Our prof was perfectly safe, by laws of nature. There was no miracle, just good didacticism.
Carl Sagan described just such a demonstration in one of his novels, written decades after I saw Sachs do the above.
Sachs never claimed to have originated the demonstration: his own professor have have done something similar in the ‘Forties, or in the ‘Thirties …