The parable of the 'Celestial City'
Two men traveling on a road
Traveler A believes that the road leads to a city, Traveler B believes the road leads to nowhere
Along the road, they experience "refreshment and delight" and "hardship and danger"
If Traveler A is correct, they will eventually arrive at this city
If Traveler B is correct, they wil keep going forever, and neither will be proved right