This is a difficult topic which I have been studying for some time. "Natural
Revelation" as I have understood it for some time is also "universal
revelation". Nature is there for all to see that God was the creator but most
people "suppress" the truth because of their wickedness. God will only make
us accountable for what we have done (I'm not talking about salvation but
accountability for actions), in order for humankind to be inexcusably guilty
before God an inexcusable action must take place - suppressing the truth -
replacing the glory of God for reptiles and quadrupeds. I agree that "the
unbeliever will not come to a knowledge of God through nature", especially
saving knowledge, but she is certainly aware of God because of nature.
Mankind is incapable of seeing the God of creation only after they have
suppress the truth and God has gave them over. God is sovereign in salvation
(I firmly believe) so I'm not discussing this issue, but I'm saying that
nature reveals God to all but not all the time, but a chance has been given to
all to see. This is why I reacted to your statement:
"I agree that evidences of theistic creation are indeed everywhere - but only
and I may add these evidences are also there for the unbeliever before she
decides to suppress them.
In any case, notice that the inability of the unbeliever to see God in
creation is not intellectually caused/rooted but morally caused/rooted.