2 Thessalonians 2:15
2 Thessalonians 2:1515Therefore, brothers, stand firm and cling to the traditions we taught you, whether by speech or by letter.
— "hold the traditions you were taught, whether by a spoken message or by a letter from us" — is a Watchtower defence text for the ongoing "channel of communication" concept. Ongoing direction from the Governing Body is framed as the modern continuation of the apostolic paradosis Paul authorised. The "spoken or written" distinction is read as two separate streams, and the Watchtower claims custody of the oral stream.
Verse 15 is interpreted by verse 5 of the same chapter, where Paul explicitly says his oral teaching and his written teaching carried the same content ("do you not remember that I told you these things while I was still with you?"). The "word or letter" distinction in verse 15 is about mode of delivery, not two separate streams of apostolic revelation with different material. The paradosis — that you were taught in the perfect passive — is specifically what the apostles delivered during their own lifetimes. Jude 3 then closes the deposit: "the faith entrusted once for all to the saints." The Greek hapax is emphatic — singular, complete, sealed.
The gentle, falsifiable question for the doorstep: "Can you name one specific apostolic tradition that Paul, Peter, or John delivered orally — a tradition that is not in the New Testament — and show me how you know the Governing Body has preserved it faithfully from the first century until today?" There is no such named tradition. Every doctrine the Watchtower teaches that differs from the New Testament is either a new teaching or a reversal of a previous teaching — not the preservation of something the apostles delivered. That silence is the answer. Then in the NWT completes it: scripture makes the person of God "fully competent, completely equipped for every good work." No oral-stream supplement is required.