That will actually happen in this case, BTW:
This is why I've always maintained that it would be pointless for God to come down and do a great miracle so everyone would believe. Disbelief would immediately set it in, and within a handful of generations man would be right back to where he is now, wondering why God doesn't show Himself and insisting the evidence of the past is false. The point remains, though, that not having the same experience as another person in no way invalidates their experience.
There is something else to point out.
I made the assumption that eventually every tribesman will see an airplane earlier. I can be wrong.
If no planes fly over the area the tribe inhabits, they too, will not come to believe in the existence of airplanes.
This leads to an interesting question: Without 'proof' of airplanes, why are airplanes important to the tribe?
God has to established existence in order for that quote to become fulfilled. Until then, if there is a then, treating God like God does not exist does not affect the 'tribe'.
On the contrary, pretending God does not exist removes incentive for man to act in any way other than selfishly. Atheists become agitated when that is pointed out to them, because they want to be seen as good people. Why, if God doesn't exist and there's nothing beyond this short life, is not evident.
1st: God has to establish the self to humans in order for humans to respond to God and God's wishes. You do understand why? Anyone can write a book, proclaim visions, or claim to speak for God and all can be lying. God has to authenticate each message, else it is most likely false.
2nd I don't see how a person behavior actually changes..
Even if you do believe in God, you act in a selfish manner if you choose to follow this God or not.(If you can, since God still has to establish first himself in order to command you)
3rd Why are you fascinated about death when you still have this life to live.?
I think you are adding topics here, I think the topic was about the existence of a God and why this God has to establish himself. Not assumed benefits to believing in a particular God that may or may not exist due to the fact it has not establish to all humans, but a seleclt few(if they are telling the truth)