"By the Waters of Babylon" is a short story by Stephen Vincent Benét. The main character, John, is a priest and a priest's son who has lived in a post-apocalyptic world. He decides to travel to a forbidden place, a place where it is believed by himself and his people that gods used to live. After crossing the river Hudson and reaching New York, John finds out that the beings they believed to be gods were, in truth, men like himself and his peers. He realizes there are no demons haunting the place and also becomes aware of the fact that his people should be able to build great buildings and work with metal just like men used to do in the past.
In the excerpt, John has just returned home and told his father what he has seen. His father cautions him not to tell others the same way he told him. Since people have been living with wrong convictions for so long, they will probably not be able to take it all in at once, and might even doubt John, call him a liar or a crazy man. But if the truth is revealed little by little, people may get used to the idea that men caused their own destruction and that they are able to rebuild the world. Therefore, the best option seems to be: facing the truth is not an easy task.