What do you think revelation is? Do you think men look at nature, and on their own realize there is a god?
What does it SAY?
" 18For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth. 19For what can be known about God is plain to them, because God has shown it to them."
Pull off your Calvin blinders and READ!
Yes.
"Pull off your Calvin blinders and READ!"
For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves. Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the meanwhile accusing or else excusing one another.