The book of Jonah has one main point – God’s love for the world. This is seen in the fact that he wants to save the city of Nineveh from divine destruction. To this end, he sends Jonah, a prophet of God to warn the people. Of course, the drama thickens, because Jonah is such a reluctant prophet. However, God brings Jonah around and in spite of his hardened heart, God uses him as a vehicle of salvation. What makes Jonah come around is that he is swallowed by a fish. During this time (Jonah 2), Jonah experiences a symbolic death and resurrection. In poetic form, Jonah states that the earth has barred him in forever. However, as Jonah prays to God, he experiences a miracle; he gets out of the fish. In short, his life is given back. It is at this point that he goes to Nineveh. What makes this story even more interesting is that Jesus quotes Jonah (Matthew 12:38) and states that he would be in the belly of the earth for three days as Jonah was in the belly of the earth. The point that Jesus is making is that he, too, will experience a death and resurrection to save his people. This is how Matthew takes it.
The story of Jonah and the whale is basically a story of a man's rebellion and how God taught him a lesson he never forgot.
Jonah was a prophet of God. God told him to go to Ninevah, a very wicked city in those days, and preach to the people. Jonah knew it was a wicked city and didn't think his preaching to them would do any good. So, he refused and got on a ship to escape from God (or so he thought). The ship sailed out into the Mediterranean Sea and a storm came up. It was so bad that it looked like the ship might sink. The sailors, who were a very superstitious lot, declared that someone or something on board the ship had cursed it. They cast lots to determine what or who it was and the lot pointed to Jonah. Jonah knew it was best for the good of ship that they throw him overboard, so they did.
As Jonah sank down into the depths of the sea, a "large fish" swallowed him. (I've always been taught that it was a whale that swallowed him.) He remained in the belly of the whale for several days until God commanded the "fish" to spit him out on land. Jonah was so humbled by the experience that he went and preached to Ninevah. To his surprise, the whole city was converted!
Instead of being happy, he was cross and went and sat under a vine along the highway. During the night, a worm bit off the vine and it withered, leaving him to sweat in the hot sun. Then, God came to him and explained to him that it was by God's power that all things are done. Just like Jonah couldn't keep the vine alive, he couldn't have control over which people believed in God's word. What God expected from Him was to do His will and Him control the outcome of it. Jonah needed to give the glory and honor to God.