Does God Leave People in the Dark?

The world of the Bible is very small. It covers only the Middle East, Northeast Africa, Eastern Europe around the Black Sea, and the Mediterranean. As a result, everything described in it makes no mention whatsoever of the far eastern nations like China and Japan, nor the far western nations on the yet-to-be-discovered continents of the Americas. Since the First Nations have been in our part of the world for at least 11,000 years, and Abraham doesn't make his appearance until 4,000 years ago, what was going on here the whole time the story of the Bible was happening? Were the First Nations just in the dark about God altogether? What would be a good way for us to consider what they had learned about God long before anyone showed up to tell them about Jesus?