Re Romans: In general terms Paul continues to lay out how life in the Messiah (Christ) works, now focusing on Torah. In 5:20 Torah appears—surprisingly—in the minus column; here Paul provides the rationale.
Coming at the text from the Old Testament with its profound appreciation for and delight in Torah, it’s extraordinary. What is Paul thinking? Dunn notes the then-prevalent opinion that covetousness was the root of sin (cf. James 1:15) and argues that the text is a close reading of Genesis 3:1-7—worth considering. Behind this reading, perhaps Paul’s experience of the temptation to arrogance vis à vis the gentiles Torah offered (Dunn again), or the misreadings of Torah that drove Jesus’ death and Paul’s persecutions of the churches.
Or perhaps a close reading of Ps 19:7-13. Beginning with v.7 there’s one of the most profound celebrations of Torah:
7 The law of the LORD is perfect, reviving the soul;
the decrees of the LORD are sure, making wise the simple;
8 the precepts of the LORD are right, rejoicing the heart;
the commandment of the LORD is clear, enlightening the eyes;
Similarly, vv.9-11. But then the surprising vv.12-13:
12 But can anyone know what they’ve accidentally done wrong?
Clear me of any unknown sin
13 and save your servant from willful sins.
Don’t let them rule me.
Then I’ll be completely blameless;
I’ll be innocent of great wrongdoing. (CEB)
Torah can name sin; it cannot check it—or vv.12-13 would be unnecessary. And this sounds rather like what Paul is arguing in Romans 7.
But vv.7-8: do we experience Torah, or, more broadly, the moral law, working this way? Byrne’s suggestion is perhaps worth considering: “What would seem to be in mind is the idea that the prohibition, stemming from God, awoke a latent human propensity to chafe and rebel at creaturely dependence upon the Creator. In this ‘I’ came to know and feel the fundamental ‘desire’ lying behind all concrete acts of wrongdoing: the desire to possess whatever I wish and to do whatever I choose without limit.”