Urban C. Von Wahlde wrote the following criteria one should use for evaluating proposals of anti-Docetism in Johannine literature. I believe it is useful and can be transposed for other proposals (e.g., if the Book of Mormon addresses topic ‘x’):
I would propose that among the
criteria for evaluating the proposal of Docetism or anti-Docetism in the Johannine
literature one of the primary ones should be how much of either 1 John or the
Gospel of John is taken into account in identifying the opponents. While it is
not impossible that only a limited part of the document concerns. Docetism, it
is important to question such limiting of the evidence since such limiting can
potentially lead to theories that only account for part of the actual evidence,
resulting in distorted conclusions.
Second, how well does the proposed
solution account for the data: Are there texts that are not explained—or are
explained only awkwardly—by a given explanation?
Third, if an explanation accounts
for a variety of features not only in one document but in more than one, that
explanation should ordinarily be considered the more likely.
Fourth, if a document is said to
be anti-Docetic, we should expect the document to confront a substantial number
of features that are known to be characteristic of Docetism.
Fifth, if reputable scholars are
divided among themselves regarding the interpretation of the same body of evidence,
we must inevitably ask what there is about the document in question that allows
for such radically different interpretations of the same data. (Urban C. Von
Wahlde, Gnosticism, Docetism, and the Judaisms of the First Century: The
Search for the Wider Context of the Johannine Literature and Why It Matters [Library
of New Testament Studies 517; London: T&T Clark, 2015, 2016], 65)