Romans 1-2 are like a one-two punch, Paul's prophetic trap to bring his Jewish readers to a shock of repentance.

First he gives a blistering indictment of the world. It's dominated by idolatry, sexual perversion, depravity and all unrighteousness (Romans 1:18-32). It's an indictment that every Jew would agree with. Many of them had read something similar before, in words of the intertestamental period.

But Paul embeds a time bomb in the indictment. Speaking of idolatry, he says that human beings have "exchanged the glory of the incorruptible God for an image in the form of corruptible man and of birds and of four-footed animals and crawling creatures" (Romans 1:23). It's a virtual quotation from Psalm 106. But Psalm 106 isn't talking about pagan idolaters. It's talking about Israel's rebellion in the wilderness.

That's the clearest indication that Paul includes Israel in his indictment, but it encourages to find other hints. Paul condemns greed, but the gospels tell us that the Pharisees were lovers of money. Paul says God gave people over to murder, but the Jewish leaders were like their father the devil, who was a murderer from the beginning. We begin to wonder if "haters of God" (Romans 1:30) is a description of Jews even more than of Gentiles.

An inattentive hearer or reader might miss this. A Jewish hearer would likely start cheering Paul on: Yes, that's exactly what the gentile world is like. You go get 'em, Paul.

But Paul's setting them up. He gets the cheering along, condemning the horrors of the Gentiles, and then turns the tables: "What about you Jews? You've got the Law, you boast in God, you have a mission to be light in the darkness and guides to the blind. Don't you do the very things you condemn in others?" (Romans 2:17-23).

Paul's rhetoric is like Nathan's to David. Tell a story that rouses the king's outrage, and then spring the punch line: "Thou art the man."

One of the most damning things is that those horrible Gentiles actually do a better job than the Jews. That's what Paul says in Romans 2:14-15. These verses have often been read in support of natural law, but that's a misreading. As N.T. Wright has said, Paul isn't talking about "Gentiles doing the law by nature" but "Gentiles who do not have the law by nature doing what it requires." This is the paradox: Those who are "Jews by nature," by genealogy and birth, don't do the law, while "Gentiles by nature" do.

How do these Gentiles-by-nature do the law? It's written on their hearts. That's not a reference to their possession of natural moral sense. Having the law written on the heart is a new covenant blessing (Jeremiah 31:33). That blessing has extended to Gentiles, who now put the Jews to shame by their obedience. Some Gentiles praise the God of Israel, but not because of Israel's faithfulness. Jews have provoked more blasphemy than praise among the nations (Romans 2:24).

The failure of the Jews sets up one of the main themes of Romans. Paul's letter answers the question, How can a just God justify sinners? But we'll miss much of the letter if we don't see that he's answering another dilemma too: How can God save the Gentiles if Israel has failed?

As Wright argues, Paul assumes the promise that Abraham would bring blessing to the nations. Israel is Yahweh's agent to save the nations. What happens when Israel herself needs saving? Salvation is of the Jews. How can God save if the Jews themselves failed in their mission?

The stunning good news is that even the defection of Israel doesn't stop God from fulfilling His promise. He can turn their stumbling into the salvation of the world. This is the good news of God's justice, that He remains true even though all men - even His own - are liars.