Paul’s explanation of the gospel starts off with the need for salvation (or the why). In the case of the cross, the good news is only necessary on account of the bad news. It is the sinful state of man that lends itself to the need for a savior. John MacArthur puts it nicely: “We cannot appreciate the wonder of GOD’s grace and love until we truly understand GOD’s righteous anger against sin. We cannot appreciate GOD’s forgiveness until we appreciate the eternal consequences of sin.”
Paul begins the body of his letter by proving the sin of man (focusing on Gentiles in 1:18f and Jews in 2:1 – 3:20) and by announcing the resulting punishment thereof – the wrath of GOD (1:18) and the judgment of GOD (2:2). The section closes with an introduction into the righteousness of GOD through faith in Jesus Christ (3:21 – 26); setting the stage for the example of Abraham in chapter four.
2:9 – 10 serves as a key verse for the section: “There will be tribulation and distress for every human being who does evil, the Jew first and also the Greek, but glory and honor and peace for everyone who does good, the Jew first and also the Greek.”