An easy parlor trick, especially amongst drunken primitives. Perhaps a little flavoring, or even hypnosis. It's not hard to see that soon we'll be able to manipulate molecules at the atomic level as easily as a child builds with Legos. Perhaps a combination of certain chemical reactions taking place in the brain could trigger it. It is an excellent depiction of just how easily so-called miracles can be performed with just the slightest bit of technology and planning.
Religion is basically a crutch.
It allows the faithful to abdicate all responsibility for their failures. It wasn't God's will. With this simple little fallacy, the true believer can go through life blissfully ignorant of their own shortcomings. Truly, He works in strange and mysterious ways. It must be nice to go through life thinking it's never your fault.