In the classic science fiction story "Nightfall" by Isaac Asimov, the author posits a world with six suns in which darkness only appears once every 2,049 years. Most people are completely ignorant of this phenomenon, but two groups believe that the next darkness is soon to come: the scientists and the cultists. The scientists have used what they know of the laws of gravitation to predict when the darkness will occur, while the cultists rely on a volume known as the Book of Revelations. They believe it contains prophecies that the world will go through a cave of darkness in which sacred stars will appear and take the souls of believers to paradise.
All of this is necessary background if you are to take the position of one of the cultists in your essay. The scientists have also studied the Book of Revelations and realize that some of the prophecies may be based on fact. However, the cultists reject the findings of the scientists because they take away the element of faith from the cultists' beliefs.
As you write your essay, keep in mind that the cultists are fanatics whose beliefs are so strong that they reject facts. Latimer, the cultist who is captured when he attempts to sabotage the observatory, makes it clear that they don't care if the scientists prove their prophecies or not. He emphasizes that the truth "stands proven by the Book of Revelations" and that there is no need for any other evidence. In fact, he attempts to destroy the scientific evidence because the cultists consider it blasphemy. Latimer calls it "a fraud and a delusion."
After Latimer is captured and promises not to interfere with the scientists, he quotes a long section from the Book of Revelations. If you study this passage carefully, you may find information you can use in taking the role of a cultist. Remember that to a cultist, the darkness caused by the eclipse cannot be explained by science. Instead, it has supernatural significance and heralds the end of the world.