Did Jonah fail the test of a prophet? I came across an article on the FAIR Mormon wiki that discusses the prophetic test (Deut. 18). It applies the test on some Biblical prophets, and shows how someone could claim these prophets fail the test.

The one I find interesting is Jonah's prophecy against Nineveh:


  Jonah 3 (ESV)
   1 Then the word of the LORD came to Jonah the second time, saying, 2 "Arise, go to Nineveh, that great city, and call out against it the message that I tell you." 3 So Jonah arose and went to Nineveh, according to the word of the LORD. Now Nineveh was an exceedingly great city, three days’ journey in breadth. 4 Jonah began to go into the city, going a day’s journey. And he called out, "Yet forty days, and Nineveh shall be overthrown!"   


What did happen was that the people of Nineveh repented and God did not destroy the city:


  10 When God saw what they did, how they turned from their evil way, God relented of the disaster that he had said he would do to them, and he did not do it.   


I'm interested in the Protestant answers to the following questions:


How does this fit with Deut. 18, where God says that if the word of a prophet doesn't come to pass, it's not from the Lord?
Should the inhabitants of Nineveh have considered Jonah as a false prophet?
Should we consider Jonah as a false prophet?


For reference, the passage from Deuteronomy:


  Deuteronomy 18:20-22 (ESV)
   20  But the prophet who presumes to speak a word in my name that I have not commanded him to speak, or who speaks in the name of other gods, that same prophet shall die.' 21 And if you say in your heart, 'How may we know the word that the LORD has not spoken?'— 22  when a prophet speaks in the name of the LORD, if the word does not come to pass or come true, that is a word that the LORD has not spoken; the prophet has spoken it presumptuously. You need not be afraid of him.
What's clear from the account of Jonah is that God would have destroyed the city if it were not for the people's repentance. Jonah's prophecy was accurate in that it articulated what God was going to do, but God relented. There was no failing in Jonah's ability to discern and communicate the will of God prior to the people's repentance, but that remarkable repentance was a hugely significant event that altered the subsequent history of that city.

There is a bit of chicken-and-egg here. God could of course have prevented Jonah from making this prophecy since he knew the people would repent, in which case the people of Nineveh wouldn't have heard about what God had in store for them. They therefore might not have repented, and the city would have been destroyed... it's similar to the liar paradox. In other words, the people needed to hear Jonah tell them what was in store if they didn't repent in order to repent: the prophecy was conditional.

You could also argue that Jonah's prophecy holds true: the city was overthrown within 40 days, but in a spiritual sense rather than a physical one.

In the case of Joseph Smith, those who maintain he was a false prophet argue there were no such events that altered history in the same way yet still his prophecies did not come to pass; this isn't a case of God relenting, it's simply a case of getting it wrong in the first place. (Mormons of course disagree and maintain that some of his prophecies were later cancelled and others came to pass to a certain degree).

There are several supporting online resources... these are from a Google search, so  may not all be representative of mainstream Christianity: Let Us Reason Ministries | Christian Research Institute | Third Millennium Ministries | Mormonism Research Ministry