What does Romans 2:3 mean?
In the previous verse, Paul declared what he assumes his readers know and understand: God judges people for practicing sin. Now Paul asks a direct question: Do you think you are exempt from God's judgment for sin?Why would anyone think they could escape God's judgment? As Paul showed in Romans 1, Gentiles may think this because they have rejected the very idea of God. He insists they are wrong. Now he comes to his Jewish readers. They may make the mistake of thinking God won't judge them for their sin either because they don't think themselves sinful or because they think He won't judge Jewish people. Paul will show they are wrong on both counts.
God will judge everyone one of us, Jewish or not, for our sinful practices. And we all commit sins, a point Paul will make later in this letter (Romans 3:23). All of this supports the central idea of this letter: that salvation is by grace alone, through faith alone, in Christ alone.