St Paul, when he went to speak to the Greeks, walked passed a series of altars to the various gods of the Greeks. As he did so he noticed one altar with nothing on it and the inscription said, “To the unknown god”.
Paul counted this to the credit of the Greeks and used it as a jumping off point for his evangelization. But why did He count it a credit? Because it demonstrated that the Greeks were open minded. They were able to say, “There may be a god we know nothing of” and then they would, by their methods of discussion, debate and study, try to learn more.
In the same way, a person who has never hear of Christ, or has only heard inaccurate snippets, might actually grow into a knowledge of God without even realizing it, so that if and when someone were to point to 1 John 4:8 “…God is Love” they might cry with the Greeks, Eureka!!!