Many people find it hard to believe the story of Jonah and the whale. I find that less difficult than the entire city of Ninevah, including tis rulers, repenting. In three days. I know of nations that convert from paganism -- the Fijians, the Samoans, the Tongans, the Maori -- but that often came after a generation of grief for missionaries. It was not instataneous.
But our God can do miracles, and he is patient, waiting and allowing us to turn to him, as individual souls, as cities, and as nations.
3 Then the word of the Lord came to Jonah the second time, saying, 2 “Arise, go to Nineveh, that great city, and call out against it the message that I tell you.” 3 So Jonah arose and went to Nineveh, according to the word of the Lord. Now Nineveh was an exceedingly great city,[a] three days' journey in breadth.[b] 4 Jonah began to go into the city, going a day's journey. And he called out, “Yet forty days, and Nineveh shall be overthrown!” 5 And the people of Nineveh believed God. They called for a fast and put on sackcloth, from the greatest of them to the least of them.
6 The word reached[c] the king of Nineveh, and he arose from his throne, removed his robe, covered himself with sackcloth, and sat in ashes. 7 And he issued a proclamation and published through Nineveh, “By the decree of the king and his nobles: Let neither man nor beast, herd nor flock, taste anything. Let them not feed or drink water, 8 but let man and beast be covered with sackcloth, and let them call out mightily to God. Let everyone turn from his evil way and from the violence that is in his hands. 9 Who knows? God may turn and relent and turn from his fierce anger, so that we may not perish.”
10 When God saw what they did, how they turned from their evil way, God relented of the disaster that he had said he would do to them, and he did not do it.
2 Peter 3:8-13
8 But do not overlook this one fact, beloved, that with the Lord one day is as a thousand years, and a thousand years as one day. 9 The Lord is not slow to fulfill his promise as some count slowness, but is patient toward you, not wishing that any should perish, but that all should reach repentance. 10 But the day of the Lord will come like a thief, and then the heavens will pass away with a roar, and the heavenly bodies will be burned up and dissolved, and the earth and the works that are done on it will be exposed.
11 Since all these things are thus to be dissolved, what sort of people ought you to be in lives of holiness and godliness, 12 waiting for and hastening the coming of the day of God, because of which the heavens will be set on fire and dissolved, and the heavenly bodies will melt as they burn! 13 But according to his promise we are waiting for new heavens and a new earth in which righteousness dwells.