Romans 2: 12 For all those who sinned without law will also perish without law; but all those who sinned under law will be judged by law. 13 For the hearers of law are not the ones righteous before God, but the doers of law will be declared righteous. 14 For when people of the nations, who do not have law, do by nature the things of the law, these people, although not having law, are a law to themselves. 15 They are the very ones who demonstrate the matter of the law to be written in their hearts, while their conscience is bearing witness with them, and by their own thoughts they are being accused or even excused.
That passage deals with those who have never been given the law but who act in a good an moral way. It doesn't say anything about rejecting the existence of God. I would say that in your case, since you've been given the information and reject it, that you won't be extended the latitude of those who never heard the law.