So the first principle of informed skepticism — which, we must remember, is supposed to be attitude that drives us as we perform the Outsider Test — is this:
[I]t assumes that one’s own religious belief has the burden of proof
Which, if we take it precisely literally, is simply another example where Loftus explicitly asks that we not treat our own religious beliefs the way we treat other religious beliefs. So I think the best way to interpret this is that we treat all religious claims as if they have an equal burden of proof, meaning that if you claim that one religious belief has insufficient evidence to meet the burden of proof, then you cannot accept any other religion that does not have more evidence and that does not meet that burden of proof.
At first blush, this does not seem unreasonable. The problem when we go deeper, though, is that we don’t really have a situation where we have some kind of set burden of proof and a clear set of evidence that either meets or fails to meet that. Science might have something like that, but philosophy raises far more skeptical doubts and everyday reasoning has so much more to consider that it can only have a rough-and-ready set of methods that produces beliefs that, generally, work out. (And one of those methods is, in fact, cultural transmission.) What we have when it comes to religion is a bunch of beliefs that as far as we can tell have some evidence and argument both for and against their truth and where that evidence is, I’d say, roughly equal: none of the remaining ones are known to be true … or known to be false. That includes the claim that no theistic God exists.
So, what we have is a belief formed by one of the mechanisms that generally works for everyday reasoning: cultural transmission. Yes, some of the beliefs that we inherit from our culture are false, but a lot of them are true or, at least, work out well enough that we need to use them to navigate our everyday lives until something better comes along. Pretty much all folk views do this, even to the point of maintaining beliefs that are at least inconsistent if not false because we don’t have a better option to get through the day. So now we turn our attention to alternative religious beliefs, and note that those who believe them got them mostly from cultural transmission like we did … and that those beliefs are no better evidenced than the ones we hold. Loftus would insist that in a case like this that we should at least abandon all religious beliefs, because none of them meet the artificial “burden of proof”. But in general, we do deal with methodologies or ways of knowing or believing, not probabilistic calculations. And so why shouldn’t we trust the transmissions of the culture that we are in and has formed the basis of so many of our beliefs? Plantinga is right here. If I trust, in general, the beliefs that I absorbed from my parents, my upbringing, and my culture, the fact that other cultures transmit different beliefs to those in them can do nothing to undercut my own confidence in my own beliefs. And if I am not confident in at least that cultural belief, then I already have reason to doubt and so have no need to consider that other cultures believe differently.
This holds at the level of everyday reasoning, the methods I use to navigate the world and that produce knowledge and beliefs, and justify each to the level where they deserve to be. Things are different at the philosophical level, and in this case at the level of philosophy of religion. There, all religious beliefs are treated equally skeptically and one cannot use a default against anyone. Sure, one can have one’s own personal preference for what will be the right answer, and work to defend it against challenges, but overall in terms of the field the one religion will not be accepted until it meets the set burden of proof that means that we know that it is the true one … and that includes us coming to know that none of them can be true. Ultimately, if we want to solve the problem of religious diversity, we don’t want to come at it at an individual level, at the level of everyday reasoning, but with the full resources of academic and intellectual reasoning … which, right now, means philosophy of religion.
And yet, so many atheists want to try to solve the problem of religious diversity by holding everyday beliefs and reasoning to academic and intellectual scrutiny … and ignoring or dismissing the work done by philosophy of religion and theology aimed precisely at that sort of scrutiny — and in answering it. They say that they want to address what the real religious believer believes and not the philosophized versions that theology and philosophy of religion produce, which is about as ridiculous as saying that we want to address the theory of evolution as understood by the common person and not by evolutionary biologists. Essentially, what they want to do is subject everyday or folk reasoning to scrutiny that it never does and is obviously not prepared for, avoid the responses of the fields that do that scrutiny and have prepared answers, and then insist that if you can’t address the challenges at that level that you must reject the beliefs as false. This seems to be a prime example of “stacking the deck”.
“The Outsider Test” is philosophy of religion. It also relies on an epistemology that applies to philosophy of religion and not to folk religion. Thus, it is at the level of philosophy of religion that this battle will be fought, and the problem of religious diversity solved. No where else.