Far not all people have enough education in physics and math to explain how nature work. So, when they see or experience something UNEXPLAINABLE to them (complex natural phenomenon, magician or other tricks, miracles, visions, voices, etc. - what should they think? They do not know physiology, hypnosis, etc. - thus, naturally they think that "there is something unexplainable out there". Not knowing that it has already been explained, they think that those phenomena CAN NOT IN PRINCIPLE BE EXPLAINED by natural laws, and thus they conclude that it is God's (or Devil's, or angel's) business. Especially if they WERE TOLD it is.

Sama as child who does not know where Cristmas gifts come from and who was TOLD they come from Santa, begin to suspect that may be indeed there is some Santa out there. How does he figure out that there is non? Only by learning where actually toys come from. But FAR not all people learn where do phenomena come from, so they naturally remain in "God makes that thunder" or "God makes those 19 constants" state (more or less).