Perhaps you may wish to read again this brief book before thinking about these final thoughts. Here are a few.
First, Jonah’s experiences warn us about the danger of a wrong concept of God. As far as Jonah was concerned, the wrong concept was nationalism. It was not the case that Jonah was ignorant of the character of God, but he had not allowed his intellect to affect his attitude. His knowledge about God did not cause him to understand God. He knew God was gracious, yet did not think he should be gracious to Nineveh. There is a real danger of having a detached knowledge of God that does not transform us into his image.
Second, God would not let Jonah go on in his downward path. He took steps in providence to arrest that descent as well as interacting with him personally. In a way, this is probably the most encouraging message of the book as far as the personal lives of believers are concerned. If you belong to God, he will not let you go. He may allow you to begin a descent, but he will not let you go down to the bottom. Eventually he will restore you. And he will not do so only once. Again and again he will restore his people.
Third, Jonah is an example of a preacher not being blessed by his own message. This is a danger that faces all preachers and may not be recognised by their hearers. No doubt, his converts in Nineveh were thanking God for Jonah’s ministry, yet Jonah was not interested. He had preached with benefit to others, but with no benefit to himself. It is important that you pray for blessing on the ministry from the pulpit, but you should also pray for blessing in the pulpit.
Fourth, we can be encouraged by realising that God can use a disobedient servant. This does not justify disobedience, but which of us is perfect? Our gracious God sidesteps the barriers that we erect and continues to use us in his service.
The book closes with God asking Jonah a question regarding the fate of the thousands in Nineveh. One assumes that Jonah realised the suitability of closing the account with a question. I suspect he finished his story in this way in order to help his readers grasp the most important detail of his book. If we come away saying that the most amazing feature of this story is the provision of a whale, we have missed the point of the book. Instead we are to focus on the amazing fact that the God of Israel blessed repentant pagans with mercy. The reason the book closes with an unanswered question is because the Lord wants us to give our answer to what he will do in our Nineveh.