In the second chapter of Romans Paul lays out the simple fact that we’ll be judged by God. His judgment is righteous and just, and nothing can supposedly save you from that judgment. Being circumcised won’t save you. Even pleading ignorance won’t save you, for you will be judged by your own conscience. Paul understands human nature and is trying to make sure the Romans know that they don’t have a “get of jail free” card. Even those who know the law and teach the law do not follow the law.
Oddly, perhaps, this reminds me of a common complaint of God and His judgment. People will say, “yeah, God’s fine, but what do you about those people who don’t hear about Jesus. Do they go to hell? Are they saved?” The legitimate question is not an easy one to answer. We really don’t know and can only throw ourselves on the mercy of Jesus Christ. Nevertheless, this question is usually asked to deflect the real question, “Do you believe and follow Jesus?” You may be troubled by the fate others, but your fate is here and now.