@SovereignGrace , It seems to me that the reason that you reject John 3:18 (as literally rendered) is simply because you cannot accept that those who have not heard the gospel message can be held guilty for rejecting Christ. This IS the point Paul was addressing. They are without guilt, period.
Salvation is NOT dependent on man, period. It is not an issue of a man deciding if he will believe or if he will not believe. You reduce the gospel down to human decision and effort - like deciding wither to have a t-bone steak or a salad. It is not that simple.
Mankind is guilty of rejecting Christ because the Godhead is known. You may not accept it, but all of Creation was created THROUGH Christ and FOR Christ. Man cannot be saved without the gospel, but man can be condemned for rejecting Christ nonetheless. All your wiggling will not change this truth.