The account of Jonah preaching destruction to the city of Nineveh is well known.  Let’s begin by reading Jonah 1:1-2, “Now the word of the LORD came unto Jonah the son of Amittai, saying, Arise, go to Nineveh, that great city, and cry against it; for their wickedness is come up before me.”  Notice that this was not a message of mercy, but of coming judgment.  Jonah, as most of us know, did not want to do the Lord’s will and took off in a ship in the opposite direction. Verse 3 tells us, “But Jonah rose up to flee unto Tarshish from the presence of the LORD, and went down to Joppa; and he found a ship going to Tarshish: so he paid the fare thereof, and went down into it, to go with them unto Tarshish from the presence of the LORD.”

In an amazing chain of events, Jonah wound up in the belly of a great fish the Lord had created for this purpose.  (Read verses 4-17).  After three days in the belly of that great fish, Jonah finally prayed to the Lord and proclaimed, “But I will sacrifice unto thee with the voice of thanksgiving; I will pay that that I have vowed. Salvation is of the LORD.” (Verse 9).  At that point, the Lord directed the fish to vomit Jonah on dry ground. (Read chapter 2.)

This time, Jonah was obedient unto the Lord.  Jonah 3:4 tells us, “And Jonah began to enter into the city a day’s journey, and he cried, and said, Yet forty days, and Nineveh shall be overthrown.”  This was not a message encouraging the citizens of Ninevah to repent.  No, it was a harsh message, letting everyone know the Lord would destroy that great city in forty days.  Yet, at the sound of impending doom, the people were drawn to repent of their sins as we read in verse 5, “So the people of Nineveh believed God, and proclaimed a fast, and put on sackcloth, from the greatest of them even to the least of them.”  What a remarkable thing…the sound of God’s wrath caused the people of Ninevah believe God, to fast, and from the least to the greatest, they repented, as shown in their wearing of sackcloth.  How did the Lord react to this repentance?  “And God saw their works, that they turned from their evil way; and God repented of the evil, that he had said that he would do unto them; and he did it not.” (Verse 10).  Grace prevailed in the face of repentance. 

Yet, as you pointed out in your question, the Lord did eventually destroy Ninevah.  The book of Nahum begins by stating, “The burden of Nineveh. The book of the vision of Nahum the Elkoshite.” (Verse 1).  This first chapter speaks of God’s goodness (slow to anger, He is good).  Yet we also read of God’s righteous judgment on the evil (He will not at all acquit the wicked, the mountains quake at Him.)  Concerning Ninevah, we read in verse 14, “And the LORD hath given a commandment concerning thee, that no more of thy name be sown: out of THE HOUSE OF THY GODS will I cut off THE GRAVEN IMAGE and THE MOLTEN IMAGE: I will make thy grave; for thou art vile.”

While The book of Jonah deals with God showing mercy on the city of Ninevah regardless of their cruelty, the entire book of Nahum outlines God’s judgment against that city.  It is estimated that there was 150 years between the events of Ninevah repenting in the book of Jonah to the Lord destroying Ninevah in the book of Nahum.  It is obvious from Nahum 1:14 (written above) that the Ninevites, even after witnessing God’s grace, had sunk into idol worship.  So much so that the Lord regarded them as VILE!  So, it was after four or five generations that these people returned to the wicked state they had been in Jonah’s day. 

God hates sin and He will judge those who won’t repent and that’s what happened to Nineveh. Does God like to judge? No, but He will not change if any kingdom refuses to repent from their sins.  My friend, what about you?  Have you repented of your sins and accepted Jesus Christ as your savior?  It is only through faith in the Lord Jesus Christ that any of us will be able to avoid the wrath of a righteous, sin hating God.  While God does not like to judge, He MUST judge sin not forgiven through faith.  Hebrews 2:3 asks the important question, “How shall we escape, if we neglect so great salvation?  (CC)  (680.4)