a solid clue

Week 43 Romans

Because I’m a 21st-century Albertan I know I’m smarter than most 1st-century guys.
So a niggling question that occurs as I read Romans is how much of this letter did Paul’s not-too-bright audience understand (because halfway through it there’s quite a bit that I’m not getting)?
Here’s an example of one of Paul’s not-too-simple ideas. He’s talking about people who turn their back on the Lord’s truth. Paul says that even though they do: the truth about God is known to them instinctively. God has put this knowledge into their hearts.
Paul says there’s an instinctive, internal apprehension that people have about the Lord’s truth. Well yeah, you think…it’s easy enough to say that something that’s non-testable and invisible exists in my heart.
But Paul understands that. He goes on to say: from the time the world was created, people have seen the earth and sky and all that God made. They can clearly see his invisible qualities – his eternal power and divine nature. So Paul shifts from the airy-fairy instincts-of-the-heart to the actual tangible earth and sky. It sounds like Paul is saying that if you look at the rock-solid material world then those rock-solids can convey a couple of ideas about what the maker-of-rock-solids is like.
The material world is a kind of subtle Visiblizing Medium that tips me off about the invisible source it came from.

Note: quotes from Romans 1:19-20 (NLT)