Once again we suffer an example of why SGU should not tread into philosophical territory. (it wouldn't be so annoying if not for the history of complaints about philosophers talking science)
(minute 25)
Emailer: "...if God were real, would you say that not all belief systems would work equally in connecting with God and living the way he desires?"
Steve: "I agree with his logic in that certainly we believe there is one reality, and that's why all of science needs to agree with itself, right?...You can't have two scientific conclusions that are mutually exclusive and yet both be correct...because it is just describing the same reality.--So, if we did live in a universe with a God, then sure--if that were part of reality--then yea it would- whatever facts there were about the existence of such a being would have to be internally consistent, and, yea, there couldn't be mutually exclusive belief systems that were both "true"."
This theological question by no means demands the same answer that one might wish to take on the presumably analogous scientific question. Where one posits naturalism, there is the natural world, and everything within it needs to be accounted for in terms of that, leaving us to produce a singular coherent picture. Where, on the other hand, the posit is of supernaturalism, as with any transcendent god concept, we are no longer limited to a worldview in which we must consider its contents to be objectively neutral, as it were--no particle of greater teleological significance than any other.
To put this into concrete terms, one conceivable apologetic for 'the problem of evil' (which is not only in general a religious apologetic but also one which can be rendered consistent with Christianity in its many forms) is what we might call the single-soul universe doctrine--solipsism for the pious. (The success or failure of this as an apologetic for the theodicy problem is not so important as its conceptual viability in abstract). One of the great problems of divine justice is that by virtue of each of us having free-will (a doctrine believed by most forms of Christian) some pious caring innocent souls end up being tormented in life, even losing their life, by consequence of other fallen men in our world 'sinning'--where is the fairness in that? why should they have to lose out just because free-will was a desired attribute? The answer is that they don't--one can conceive of a creation consistent with free-will which skirts this problem--a transcendent god produces individual 'universes' in which each single soul lives, in which everything else which peoples his world is merely a soulless creation. In each of those worlds nobody but oneself 'actually' suffers, and thus none of what looks like others suffering from the sins of still others is real. None of the sinning souls in their own worlds who harm people with their sins are actually harming any souls, depriving any souls of any good of life, because there are no other souls in their universe. We have no way of knowing if the lives of the other real souls resemble some of the miserable lives of those things which people our own universe, and thus we have no grounds to claim there is any such thing as excess or unnecessary suffering/evil in the world--there is little more than our own, which our own fondness for life proves is a minuscule thing, and a thing which in large part is a result only of our fallen nature anyway, and which can be compensated for in heaven.
There being this plurality of universes for souls also allows that any one of them might well have a different religion which is true, though if the same existed in the universe of another soul would there be the wrong one. Thus we have no grounds to accuse anyone of having the wrong religion--we do not know who is right or wrong, or who is even the mere prop in the universe of the one with the soul, so we can but have our faith, and hope we are right, and hope that in their own universe their own religion was the right one, too. Evangelism would be not only unnecessary, but futile, as any other soul which needs to be saved is within its own world in which it like oneself must find its own way.
There you have an objective Truth, a sound science, a material world, one divine God, and yet a plurality of religions each of which are as valid as the next for all intents and purposes.
Or, one could more simply say that if there is a God he isn't the model of human vices depicted in the world's religions--jealous, spiteful, greedy, needy, etc.--and therefore he doesn't care whether you were a Taoist or a Baptist, and thus in the same way reach the conclusion that any religion is as good as any other with respect to divine truth and salvation and so forth.
In other words, we have two approaches to refuting the idea of 'only one true religion': undermining either the idea of a one true nature, or the idea of a legitimate connection with one true supernature, (...or both).
The key mistake here, is best seen where he notes "if we did live in a universe with a God, then sure--if that were part of reality--then yea it would- whatever facts there were about the existence of such a being would have to be internally consistent...". There being a singular objective truth of the supernature does in no way force a singular conception of this or that nature itself in which a soul exists. Only within the posit of naturalism can one presume to say that there is one thing 'right[eous]' or 'wrong[ful]' for all.
There was also a small mistake... Where he notes "there couldn't be mutually exclusive belief systems that were both "true".". This is quite true, however it speaks past the question asked--the question isn't whether both are "true" but both "valid". It has been said 'if there is a god one might think atheism less an insult to him than religion'; that is to say, one need not conceive that God would demand one follow a strict set of ideas so much as behave in a certain way relative to his existence--one need not believe the right answer so much as follow the path which seems right. It is conceivable that many religions or lack there of which hold as true metaphysical doctrines which are inaccurate with respect to the objective supernature would nonetheless be valid to live by, in the eyes of that one objective God.
I think he came closest to a good answer with his concluding note: "with matters of faith, when there is mutually exclusive belief systems, there is no objective way for resolution--to resolve which one is correct, or which one is better". This is one step shy of our philosophical predicament--in matters of metaphysical speculation it is by no means necessary that only one is correct or better (as to which does DCT attest), and this is all the more reason why it is such a worthless endeavor--the very notions of agreement/assent/evidence/etc. come to naught even if such could be attained.