This requires you to be a sufficient domain expert to be able to:
- identify the central claims of a given religion
- identify the version of a central claim which is actually necessary for the religion
- determine what it would take to "refute" one of those claims sufficiently (rather than, for example, merely calling into question one of those claims, or refuting only one variant of a claim which has other variants.)
I contend that nobody on earth knows enough about "all religions" to be able to make such a claim. I further contend that, of the religions I mentioned above, if you didn't at least recognize the details I named, it's reasonably likely that your expertise is not deep enough to be able to follow those steps. For example, if you have never heard of The Didache, your awareness of Christianity is probably focused on only a small subgroup, whose "central claims" don't necessarily correspond to the claims of the broader religion; refuting one of that subgroup's claims may or may not have any relevance for someone from another subgroup.
I would contend in response that it's unnecessary to play whack-a-mole with countless subtle variations on the same theme if there are refutable core claims shared by a plurality of those variations. For example, the idea of a young earth is easily refuted, as are some sects' claims about the nature of human gender. Other broadly held claims, such as an unerring divine origin of scripture, lack any evidence, and thus can be dismissed, if not strictly refuted.
With regard to identifying essential claims, I'd propose that any claim that is believed by a good number of the sect's adherents is an essential claim, as refuting it invalidates those particular adherents' beliefs.
Beyond that, the question is what epistemological value can be derived from the remaining religions? What reason can be given to accept them? The burden of proof should be on them to demonstrate that they together, or one of them alone, should be accepted as accurately describing reality.
> "it's unnecessary to play whack-a-mole with countless subtle variations"
Sure -- but unless you're reasonably well-educated on a particular religion, how do you know if the variations are subtle or substantial? How do you know if they're "broadly held", particularly among that religion's scholars? (You brought up "unerring divine origin of scripture", which is a common belief of Fundamentalist Christians; do you know how broadly that belief is held by non-Fundamentalists? Do you know what the other common views are among the more populous Christian and Jewish sects regarding the same scriptures? Are you aware that Mormons believe the Bible has been corrupted?)
> "any claim that is believed by a good number of the sect's adherents is an essential claim, as refuting it invalidates those particular adherents' beliefs"
In practice, it doesn't work that way. Every religion I've studied carefully has a lot of inessential beliefs which are nonetheless widely held -- beliefs which, if they were overturned, would not in any way shake the faith of that religion's adherents.
It's common for outsiders to misidentify how popular certain beliefs are, how strongly they are held, and how essential they are. It's also common for outsiders to believe they've refuted something, when in reality they've stated some fact that has been known and accepted for centuries and which is actually the tip of the iceberg for scholarly study within a given religion.
That's why I suggest that, if you haven't heard of some of the specifics I named above, you're probably not capable of actually refuting those religions. It's not that those things are critical, so much as that to identify and address the actual core beliefs in relevant ways requires a depth of knowledge which would also expose you to topics like the Didache, the Seer Stone, or the Midrash. (And I wouldn't dream of making any sort of claim about the refutability of "all" African tribal religions, or "all" eastern religions, because I don't have that sort of depth of knowledge. I can say that I don't presently believe any of them, but that's a much weaker claim than "they're all irrational and a disease".)
> "The burden of proof should be ... to demonstrate that they ... accurately describing reality"
This ties us back to my original contribution to this discussion. How does one demonstrate that their position accurately describes reality, to an audience that thinks they are "motivated solely by stupidity"? How does one demonstrate there is value to be found in their belief system to someone who issues blanket dismissals? How does either party get value out of a conversation if one of them believes it's a monologue -- an opportunity to tell their stupid opponent how wrong they are, with no expectation that they might learn something?
If you begin with the assumption that someone else is stupid and you don't need to listen carefully to them, whether you're talking about their religion or politics or software, then it's unlikely you'll go through the sort of critical thinking process the original article described (and likely you'll "get lazy about challenging your own assumptions".)
- identify the central claims of a given religion
- identify the version of a central claim which is actually necessary for the religion
- determine what it would take to "refute" one of those claims sufficiently (rather than, for example, merely calling into question one of those claims, or refuting only one variant of a claim which has other variants.)
I contend that nobody on earth knows enough about "all religions" to be able to make such a claim. I further contend that, of the religions I mentioned above, if you didn't at least recognize the details I named, it's reasonably likely that your expertise is not deep enough to be able to follow those steps. For example, if you have never heard of The Didache, your awareness of Christianity is probably focused on only a small subgroup, whose "central claims" don't necessarily correspond to the claims of the broader religion; refuting one of that subgroup's claims may or may not have any relevance for someone from another subgroup.