Audio commentary on this verse

Note 1 at Rom. 5:12: Paul had already made a strong case for salvation by grace through faith. He used a comparison which illustrated just how great God's grace is (see note 14 at Rom. 5:7, p. 770). He now uses another comparison to make this same point. He begins making this point in this verse but inserts a parenthetical phrase in verses 13-17. Therefore, to get the complete thought Paul is bringing it helps to skip from verse 12 to verse 18.

He is saying that in the same way that we inherited the sin nature independent of our actions, we also inherit God's righteous nature, not based on our actions, through the new birth. The reasoning is that if we became sinners through what one man did, then we can also become righteous through one man, the Lord Jesus Christ.