Does Romans 1:18-21 deny the existence of "true" atheists?

I’m not certain where you are going with this. If the wrath of God is being revealed against all unrighteousness and ungodliness of men who by their unrighteousness suppress the truth, then I don’t see how anyone can escape justice, because Paul later condemns all men of being unrighteous (“There is none righteous, no, not one; there is none who understands, there is none who seeks after God.” Romans 3:10-11). He later makes the case that the only reason anyone is righteous is because of Christ’s sacrifice.

There are only two types of people in this world according to Paul: righteous, and unrighteous. The righteous are only so by God’s grace, and the unrighteous are so because they have willfully rebelled against the Creator and refuse to acknowledge Him as God (Rom. 1:21). I think Paul’s argument is rather clear.

Your thoughts?