Moreover, we should note that Jonah’s divine message had significance for all of the inhabitants of Nineveh, including the king. Nobody in that city, even the ones who may not have taken part in the overt sin of the city, could afford to ignore the message. The same is true of the gospel of Christ. It has application to each person, whether or not they were drunk or sober last night, whether or not they prayed or did not pray before they went to bed. The gospel addresses the self-righteous and the openly sinful and promises them deliverance from perishing if they will believe in Jesus.
And, we should note the size of the city in the estimation of God. In verse 3, it says that ‘Nineveh was an exceedingly great city’ – ‘exceedingly’ is literally ‘to God’. As far as God was concerned, Nineveh was important not because of its military power or political wealth but because it was inhabited by many perishing sinners. And this feature is also an essential part of the gospel. The Father gave his Son because he was concerned about a perishing world.