1 Timothy 2:5
1 Timothy 2:55For there is one God, and there is one mediator between God and men, the man Christ Jesus,
JWs cite "the man, Christ Jesus" as a creature-Christology proof — Paul emphasises Jesus' humanity ("a man") and distinguishes him from "one God" in the same verse. More importantly, Watchtower theology since at least 1934 (formalised in the 1979 Watchtower, the 1986 Worldwide Security book, and the 2010 God's Word For Us Through Jeremiah) restricts Jesus' mediatorship to the 144,000 anointed only. The "great crowd" of "other sheep" — the millions of rank-and-file JWs — are not parties to the new covenant; they are merely "beneficiaries" who receive blessings indirectly by associating with the anointed remnant. Most JWs at the door do not know this is what their organisation officially teaches.
The verse is a textbook deity-of-Christ argument when read whole. The same Greek noun anthrōpōn ("men") that defines the mediator's audience in v.5 is governed by the universal "all" in v.4 ("God desires all kinds of men to be saved") and v.6 ("a corresponding ransom for all"). Paul allows no class restriction. The verse also doubles as a Trinity-friendly proof: it places Jesus on the God-side of the God–men divide ("one God, and one mediator…") — the mediator must share both natures to bridge them, which is exactly Reformed Christology. Against the Watchtower's mediator-restriction doctrine, the verse is decisive: if Paul wanted to write "between God and the 144,000" he would have. He wrote anthrōpōn — humanity. Most JWs asked "Is Jesus your mediator?" will say yes — and the gap between their answer and the official teaching is the doorway.