The book of Jonah is unique among the Minor Prophets. Instead of a book about the prophet’s preaching, it is mainly a book about the prophet. The overall lesson of the book that Jonah needed to learn is that Yahweh is a gracious and compassionate God.
In Jonah 1, we read of the prophet’s commission to go and preach to Nineveh. Nineveh was a city in the heart of the Assyrian Empire (the ever-present threat to Israel). What does Jonah do? He runs away from God! Why? We find out in Jonah 4:2 that Jonah knew God was a “gracious and compassionate God” and that he would forgive the Ninevites if they responded to the preaching.
After God turns Jonah around to head to Nineveh and not Tarshish (1.3-2.10), Jonah finally obeys God’s command to preach to Nineveh. And they repent (3.5-10)! Jonah is angry because he doesn’t want Nineveh to be forgiven (4.1-3).
God responds, “Do you have a good reason to be angry?” (4.4). The obvious answer is no. The book ends with a rhetorical question from God, “You had compassion on the plant… should I not have compassion on Nineveh, the great city in which there are more than 12,000 persons?” (4.10-11).
Yahweh is a great God of grace and compassion. We, as His creation, have no right to say who should and should not be a recipient of that compassion. We are to preach the Gospel of grace to all so that we might save some.