I would say the book is a great testimony of the evangelism of the nations that should be done. The mercy of God shown abroad.

As to why the Ninevites, we could speculate a lot of things. Possibly to hold back the beginning of the Babylonian Empire and the captivity to follow.

I believe Jonah learned his lesson, which is why it was recorded for the Jews to learn also. To include a book that's focus is mercy, and that results in a heathen people repenting, would and should have always been a knife in the pride of the Jews that God was only interested in them.

He was sent to preach judgment (to cry out against them, because of their evil, 1:2; 3:4), but Jonah knew that God meant it for their repentance (4:1-3).

If I recall other cases would include the travels and prophesying of Elijah, and Elisha.

__________________
John Leonard
Deacon: Mid-Cities Presbyterian OPC
Bedford, TX