First I'll say that I'm not convinced either way whether or not a god exists, but these are my beliefs assuming that some all powerful god does exist:
To a god for whom creating and destroying universes is a matter of a simple thought, we are insignificant. Even though such a god may have created us he has no obligation to really care about us. Just as an analogy, I'm going to make a person (let's call him Bob) "god" and make the people of earth a school of fish. We all live in some little pond called earth. We know there exists a world outside our pond, but we can't really see very much of it, and there doesn't appear to anything living outside it from our very limited view, so we think of ourselves as somehow significant. Now, Bob owns a 40,000 acre ranch. The "earth" pond takes up an acre or two of that. At one point, Bob stocked the pond with fish.
Now, when a fish dies, should Bob even care? Even if we gave bob the power to bring them back to life by putting them in a pond called "heaven", why should he bother? If he could cause a fish eternal torment by throwing it into a pond called hell, why the hell would he do that? Can anyone see why somebody would torture an animal with an intelligence level so far beneath his own for it's misdeeds? The idea that we as people are even capable of comprehending what a god of the power required to create universes would see as good or evil is extremely self absorbed.
Why would bob even view what a fish has done as good or evil? Even if he did, why would his view coincide with what the other fish thought? Let's assume that one fish was a bully... always taking food from the other fish. Now, all the other fish dislike that fish, and think it's evil. Eventually the fish dies, Bob notices, and says "wow, that was the biggest, brightest colored fish in the pond... I think I'll throw it in the 'heaven' pond so I can watch it swim around some more".
Bob saved the fish that he liked. It had absolutely nothing to do with what the other fish viewed as "good" or "evil". Why should anyone think that a god would save people based on what other people thought? A god who thought on the same level as people would make as much sense as a rancher who thinks on the same level as a fish in his pond. The rancher has no reason to care what the fish think, and he has no reason to have any similarities in reasoning with such fish.
Anyway, I guess that means I would believe in salvation based on inherently unknown criteria, as the mind of a person cannot comprehend everything that the mind of a being who can create worlds would have to know. Heck, maybe Bob REALLY likes fish and puts them all in heaven, maybe he doesn't care about them at all anymore, and just lets them rot away in earth. How the hell should the fish presume to know how or why he would do anything. He's probably got horses and cows and things that are much more important to him than fish, anyway.
I hope that made sense... I'm kinda tired.