1 Thessalonians 5:21
1 Thessalonians 5:2121but test all things. Hold fast to what is good.
The Watchtower publicly affirms as a call to "make sure of all things" while practically restricting the scope of testing to approved Watchtower publications. Members are discouraged from consulting non-Watchtower sources about organisational teaching — such sources are labelled "apostate" and spiritually dangerous (Watchtower, 15 Jul 2011, pp. 15-16). The February 2017 Watchtower (study edition, p. 26) concedes the Governing Body "is neither inspired nor infallible, and it can err in doctrinal matters or in organisational direction," but members are simultaneously taught not to verify Watchtower claims against external sources.
The NWT at reads: "Make sure of all things; hold fast to what is fine." The Greek verb dokimazete is the assaying language of a metalworker testing gold — a rigorous, empirical, evidence-based kind of testing. Paul's imperative has no carve-out. It does not say "make sure of all things approved by the organisation," or "test only outside claims, never inside ones." The command is universal. Paired with — where the Bereans tested an inspired apostle's teaching and were praised as "noble-minded" — reveals the logical problem at the heart of Watchtower information control: a fallible authority that forbids external verification is indistinguishable from a deceptive one. Paul commands testing; the organisation forbids it. One of them must yield. The verse is also decisive in the coerced-compliance argument — Paul's test-everything mandate cannot operate in a judicial environment where openly testing a Governing Body teaching triggers a judicial committee and potential disfellowshipping. See information-control, governing-body, coerced-compliance-vs-virtue, divine-guidance-self-immunization.