 What ultimately makes the priest disbelieve what they've seen, despite his faith?
Naturally they did not get results at once, nor did they expect to; it required a fine adjustment. But this might be so varied or so unfamiliar that often both the machine and the designer of it were puzzled as to how to read the results. It was for this reason that Glaser used that model no more, but built others more amenable. And there was no denying that the Extraordinary Perception Locator (or Eppel) was a contrary machine. On Earth it had read Positive on a number of crack-pots, including Waxey Sax, a jazz tootler who could not even read music. There was a man and a woman, and they were clothed either in very bright garments or in no garments at all, but only in a very bright light.
 Someone like Adam would not be afraid of playing checkers, or being personable.
 He senses the "unusual mind" of Adam, and it made him uneasy.  He is too faithful to risk trusting what they've seen.  Someone like Adam would not be afraid of playing checkers, or being personable.  The illusion is too perfect, and it feels inauthentic to him.