Jonah lived in the Galilean city of Gath-hepher during the reign of Jeroboam II (appx. 793-746) in the northern kingdom of Israel, 2nd Kings 14:25. Which means the very people God sent him to, were going to destroy God’s children in just a couple of decades, as the Assyrians viciously conquered Israel in 722BC. Nineveh was the biggest city in Assyria, and they had a reputation for violence & world domination, so it is easy to sympathize with Jonah for being less than excited when called by God to go and help them. Jonah was a contemporary prophet alongside Hosea & Amos, both of whom declared that Jehovah would use Assyria as an instrument of punishment against Israel, Hos.11:5 & Amos 5:27) so any patriotic Israelite would have desired to see Assyria fall.
The most important detail of Jonah’s prophecy might be that Nineveh would be destroyed in 40 days, but it survived for a century & a half beyond that time. Therefore the doom predicted was conditional. Many theologians would do well to learn from this, as many theologians obviously don’t get it. For example, Israel too was promised an everlasting inheritance in the land of Canaan, but that promise was prophetically conditional as well. See Joshua 22:4, 5 & 23:1ff. The time eventually came when they lost their “deed” to Palestine, and so today and forever into the future, modern Israel has no intrinsic right to that Middle Eastern piece of real estate, they fight for it and will always fight to earn a place on the map in and around Jerusalem. Is there an innate inheritance for Israel? Obviously not, but in Jesus, they too have an opportunity to live as citizens in the New Jerusalem.
Jesus Christ believed the story of Jonah was literally true. A quick glance over the internet today shows us that most worldly people regard it as fiction. Even many theologians regard it as just an analogy and try to explain away the miracle of surviving the ordeal of being swallowed by a big sea creature. But that is the very act of God, which Jesus uses to test the faith of his disciples in his own resurrection, Matthew 12:39-41. Factually the New Testament documents that over 500 people were eye-witnesses of his literal bodily resurrection from the dead. So this makes us certain that Christ accepted Jonah’s story as literally true. God can do whatever he wants, and if you struggle with miracles, perhaps the most astounding thing to believe is that thousands of hardened idolaters in Nineveh repented of their sin & fasted, when they simply heard a single prophet preaching a message of doom. That seems far more unlikely than one person surviving the ordeal of being swallowed & vomited out by a sea creature! The hardest part of this miracle is understanding how anyone can live without oxygen for approximately 72 hours in the belly of an animal. However, that is the whole point of the miraculous experience. If Jonah prayed as he was swallowed up & then died, that means he was resurrected, then vomited out on the beach, 2:2. Which could be the reason Jesus uses it to foretell his own resurrection from the dead, as his ordeal in death on the cross was very gory too.
From God the Father’s perspective, the reason He used Jonah was to show us his sovereignty. His power over creation to accomplish his mighty message of mercy is stupendous! The Lord God controlled the elements of weather (1:4, 11, 13, 15, 4:8) and he prepared and appointed an animal, a vine and a worm to do his will (1:17, 4:6, 7) while bringing Jonah to his knees. God’s mercy triumphs over the justice Jonah was craving for in his heart. What is our heart’s desire?