Isaiah 43:10
Isaiah 43:1010“You are My witnesses,” declares the LORD, “and My servant whom I have chosen, so that you may consider and believe Me and understand that I am He. Before Me no god was formed, and after Me none will come.
This is the Watchtower's signature self-designation text. JW.org takes its name from the verse — "You are my witnesses, declares Jehovah." JWs cite the second half ("before me no god was formed, and after me there has been none") as the proof that Jehovah is the only God and that Jesus must therefore be a created being subordinate to him. The verse is treated as the keystone of strict unitarian monotheism and the charter for Jehovah's Witnesses as Jehovah's exclusive earthly organisation.
The verse is one of the cleanest deity-of-Christ texts in the OT once read in concert with the NT. The Hebrew ani hu ("I am he") is rendered egō eimi in the LXX — the same unpredicated phrase Jesus uses in , 8:58, 13:19, and 18:5-6. By picking up 's divine self-identification formula and applying it to himself in contexts where eternal destiny hangs on the hearer's response ("unless you believe that I am, you will die in your sins" — ), Jesus identifies himself with the speaker of Isaiah 43. The verse also undercuts Watchtower Christology directly: if "before me no god was formed and after me there has been none," then Jesus cannot be a "mighty god" formed before all other creatures (the Arian/Watchtower position) without contradicting Isaiah outright. Either Jesus is uncreated and shares Jehovah's identity, or is false. The witnesses Jehovah claims in v.10 are ultimately the apostles, who testify that Jesus is the one of whom Isaiah spoke.