For me (and I’d like to believe for a majority of people) it would take irrefutable proof, a preponderance of scientifically supported and testable evidence. And yet many people actually accept these things as real based on hearsay, “want-it-to-be-so”, or the flimsiest of evidence.
For these people it’s unimportant that haunted houses, fortune telling, or ESP have never passed a single controlled experiment. To the confirmed believer it’s enough to just “want to believe”, lack of genuine evidence doesn’t matter.
Imagine a child who was born to parents who were avid UFO believers; who accompanied their folks to UFO conventions from an early age; who read their parents’ UFO books and magazines of which there are thousands; who year after year overhear their parents and their parents’ friends talking about the latest sightings and the governments efforts to cover it up. What are the odds that such a child would become a dyed in the wool UFO devotee, and consider anyone who didn’t believe in UFOs deniers of “Truth”, or “deceived fools”? I’d guess damn near 100%.
Now, substitute for UFO believer parents, parent believers in God / Jesus and all the superstitious baggage that comes with it and you’d have the exact same impact on the impressionable child. The conditions that breed one irrational, unscientific, unproven, untestable belief are the same for all of them.
And just as any committed UFO freak will dismiss other popular mythical delusions as crazy and absurd, theists do the same thing by dismissing all other religions/gods as delusions or false beliefs. Coincidence? Hardly.
Even as they read this the connection will be dismissed by theists as unrelated to THEIR particular belief. Their minds can’t allow them to even acknowledge it. A blind spot in their minds.
Ok, gotta run. I have a Yeti symposium to attend. Now, those guys are the real thing.