In what sense then "should" we be able to know God from creation?
"creation" is vacuuous. That is, Paul could just as well have been
arguing that people "should" know God from blublewhipwhap, but nobody
does. Or am I missing something here??
It seems to me that Paul is arguing strongly that in a very real
sense, there is enough in creation to point us towards God. And Paul
is saying that in spite of this, gentile society as a whole has
ignored this and worshiped idols instead. This does not rule out the
possibility that there are those among the gentiles who do listen to
what creation has to say, and are found by God through it. Perhaps
Cornellius was such a man?
I agree that in Romans 1, Paul is not primarily interested in
promoting natural theology as a means for revealing God to the world ---
primarily he is demonstrating that the gentiles are without excuse.
However it does not rule out the possibility that some are drawn to
God via creation. Indeed I would go further and suggest that if there
were gentiles who rejected idols realizing that God was not the stuff
of idols, then perhaps they were ones being drawn to God via creation.
I think Paul recognized God's revelation in pagan cultures, such as
with the "alter to the unknown God".
"They told me I was gullible ... and I believed them!"