God, come out, come out wherever you are!

[Undeceived]

Let's say we have two natives in two different geographical locations. Both of them have rejected the revealed revelation of nature and have become polytheists just like the rest of their the people in their locations. So both of them, if they were to die at the same time, would wake up in hell. In one location, missionaries come and preach the gospel, and our native there hears it, believes in Jesus, and rejects his pantheon of gods. Shortly thereafter on the same day, the native happens to die, and wakes up in heaven to be with his glorious savior for all eternity. Our other native, however, also happens to die, but he winds up in hell. Is this just? It seems to me that the only reason why one native went to heaven and the other went hell is because the saved native had more information. If both had heard the gospel, both might have been saved.

It seems to me then that really the only reason in your view that a person goes to hell is because of a lack of information. Also, since in many places in the Bible, God appeared and demonstrated himself, followed by belief, then it's unfair that God doesn't show himself in the same way to everyone.

This is a hard question to answer because it relies on reading God's mind. The Bible isn't explicit on the topic of non-evangelized groups. However, Romans 9:15 has something to say on the matter. Paul on God:
"For he says to Moses, 'I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion."

In the verse, God is choosing to pardon who he pleases. Is not being evangelized to "fair"? In our way of thinking, no. But is it just? Yes. No one deserves God's gift of salvation. It isn't one's lack of information that condemns them but their original sin. Matthew 20 describes the parable of the Workers in the Vineyard. In it, the landowner offers his workers a denarius for a day of work. More workers join at noon and in the evening. Matthew 20:9-15 goes like this:

“The workers who were hired about five in the afternoon came and each received a denarius. So when those came who were hired first, they expected to receive more. But each one of them also received a denarius. When they received it, they began to grumble against the landowner. ‘These who were hired last worked only one hour,’ they said, ‘and you have made them equal to us who have borne the burden of the work and the heat of the day.’
“But he answered one of them, ‘I am not being unfair to you, friend. Didn’t you agree to work for a denarius? Take your pay and go. I want to give the one who was hired last the same as I gave you. Don’t I have the right to do what I want with my own money? Or are you envious because I am generous?’

This story is a vision of people who accept Christ early in their lives compared to people who, like the thief on the cross, ask for God's grace not long before they die. It illustrates God's idea of fairness versus mercy. Non-evangelized groups face a similar dilemma, but on the negative half of the believing continuum. If other believers and God do not bail them out, they will face their just punishment. If, however, missionaries arrive and God causes them to believe their sentences are erased (in the way that a murderer is pardoned by the president).

This view is a not conclusive, but is Bible-supported and realistic. It's also possible that God predestines future-believers to be in places where they will hear the message, and rejecters to be far-off locations the Word does not reach. Like the "God is evident to everyone everywhere" view, that is speculation.