The doctrine of justification sola fide—justification by faith alone—finds its most in-depth explanation in Scripture in the book of Romans, and so we begin our study of this precious doctrine in Romans 1. But Romans 1 does not give us the full-orbed doctrine; rather, this chapter is part of an argument that stretches some eight chapters before the Apostle is finished. He starts His explanation of the doctrine of justification in Romans 1 by explaining why justification is necessary in the first place. As we will see, the reason we need to be declared righteous before God in the gospel is because we are unrighteous before Him without it.
For a first-century Jew such as Paul, there were really only two ethnic groups—Jews and Gentiles. Romans 1:18–32 establishes that the Gentiles are sinners. Paul explains that even now the wrath of God is being revealed against all the ungodliness and unrighteousness of human beings who by this unrighteousness suppress the truth (v. 18). We read that people are guilty before our Creator because they have failed to honor God as God—they have failed to worship Him alone—and because they have not given Him the thanks He is owed (v. 21).
How does God reveal His wrath? We are accustomed to thinking of God’s wrath as the pouring out of His anger in judgment against sin. The Bible does speak of God’s wrath in this way, predicting a final day of the Lord on which the Almighty will bring great destruction on impenitent sinners (Isa. 13:9). However, we should see such descriptions of God’s wrath as the ultimate fulfillment of our Creator’s judgment against sin and sinners. That is because God is now showing His wrath in the lead-up to that final day. He does so by handing sinners over to their sin, allowing them to store up greater judgment for the day of the Lord. This is what Paul says in Romans 1. The wrath of God is revealed as God hands people over to further idolatry, homosexuality, debased minds, slander, covetousness, disobedience to parents, and a host of other sins (Rom. 1:19–31).
It is important to note that God does not give people who are unwilling to sin over to sin. His judgment, at least on this side of eternity, is to give sinners exactly what they want in preparation for the final day of judgment. And this is manifestly just, for sinners not only sin, but they take the extra step of justifying their sin and the sin of others. They approve of sin—calling evil good and good evil—and they encourage others to do so as well (v. 32).