What does Romans 1:32 mean?

Paul is referring to the long list of sins he has compiled in the previous verses. These are sins we participate in when God "steps aside," giving us what we think we want. When we ignore His truth, and twist our own minds, we suffer the natural consequences of those choices (Romans 1:18–28). This leads to sin and all sorts of moral decay (Romans 1:29–31).

Here, Paul circles back to the idea that mankind does not do these things in total ignorance. He declares again that human beings, by nature, know these things are wrong. More than that, Paul insists that even when we directly know that God has announced that those who behave in this way deserve to die, we keep doing these things, anyway! More than that, even, we also applaud other people who practice these sins.

This is Paul's short-hand condemnation of the sinful nature of mankind. However, looking at how Paul continues this discussion in the next verse (Romans 2:1), what he is really saying is "this is us." Paul's readers may have been tempted to think, "this is just about unbelievers, not us." Those religious Jews who followed the law, as Paul had once done himself, often thought of everyone else as belonging in the picture of sinful living that Paul has painted in Romans 1:18–31. In the following chapter, however, Paul will reveal that he has, in fact, been describing all of us—even those who attempt to live under the authority of the law of Moses.

It's not that we all do each of the sins listed by Paul in the previous verses. It's that the same root of sin rules in the hearts of each of us, expressing itself in some of these ways, if not others. Paul intends for us to find ourselves in his list of sinful words, actions, and lifestyles. We are all sinful, and we all deserve death.