Some people say that the Bible is just a collection of fairy tales. A boy slaying a giant. A man swallowed by a big fish. Noah's bot-building experience. Even some religious people think that these events are just nice stories with a good moral.
Jesus Himself, however, spoke of Jonah and the giant fish and Noah and the flood as actual events: "As the days of Noah were, so also will the coming of the Son of Man be. For as in the days before the flood, they were eating and drinking, marrying and giving in marriage, until the day that Noah entered the ark, and did not know until the flood came and took them all away, so also will the coming of the Son of Man be" (Matt. 24:37-39). His return will happen when we're not expecting it. Jesus compared Jonah's three days inside the big fish to the three days He would experience in the grave before His resurrection (Matt. 12:40). And Peter talked about Noah and the flood when he equated it to a future day when Jesus comes back (2 Pet. 2:4-9).
God gave us His Word. It's a book that is filled with truth - not fairy tales. And one day, we will live happily ever after with Him when Jesus comes again and receives His children to Himself. We have reason for optimism if we're looking for Christ's return.