The trouble with grobblewobble's "exhaustive" case analysis is that it completely hinges on heaven or hell, or God's intentions, being a certain way - basically it limits itself to possibilities A and B where there are many, many more, and is thus anything but exhaustive. Thats what makes it wobbly. But who am I to continue to grobble about such things?

(I am a bad person.)

If God is omnipotent, one would think that the fair thing to do would be sending messengers everywhere to give everyone a fair chance. Even today, people born in many parts of the world don't have access to the Christian doctrine at all, while other people do, that seems quite unfair.
Because Jesus is human (mostly). The only alternative would be to father multiple Jesuses. As far as I'm aware, being a heathen - i. e. not aware of the teachings of Christianity - counts as a mitigating circumstance, and if you still did good you would still get to go to heaven (and of course there are other, more restrictive views out there, I wouldn't want to believe those either). And this is also why missionaries were sent out into the world; to grant more and more people access to these teachings.