Armstrongism does not recognize the Shepherd of Hermas as Scripture. While it is an ancient Christian document, it is not part of the 66-book biblical canon and carries no doctrinal authority. The Armstrongist principle of sola scriptura (Scripture alone) limits the source of doctrine and practice strictly to the canonical 66 books, as interpreted through Armstrongist teaching.

The exclusion of post-apostolic writings from doctrinal authority is consistent with Armstrongism's critique of traditional Christianity: they claim that the early Church was corrupted by non-apostolic teachings, and only Scripture—as restored through their movement—provides true doctrine.