## That plural is a pretty certainly a “plural of deliberation” - it’s not incompatible with Christian faith in the Trinity, but whether there is a direct relation in the way seen by some, is another matter. There may be a secondary application of the text to the Trinity, given that Christ is the subject of the entire Bible - but it will, in the context of the OT, be a secondary one.
It’s important not to see NT realities in a way that entails not doing justice to what OT texts meant to OT people in OT times (so far, and in such degree, and with such probability, as that can be reconstructed). The Israelites had their own distinctive theological themes, many of which they shared with other nations, and several of which reappear in transfigured form in NT thinking & preaching: Christ is a Divine Warrior in Revelation 19; just like JHWH in Exodus 15; or Baal in various texts and art. The OT is not the NT- it looks forward, incompletely, from “various times and places” (Hebrews 1.1) to Christ-yet-to-be-Incarnate, it doesn’t draw on the riches of Christ Incarnate, Raised, and Glorified. The NT writers & churches did that - for they were in a position to see the OT & its meaning in the light of His Coming.
It was difficult enough for God to get into the heads of His people that He was uniquely and alone the One eternal God - read Isaiah 40-55. There was no shortage of Divine triads & threesomes, as the JWs are accustomed to point out. However, what they take as a Divine rebuke to belief in all trinities without exception, is as likely to be part of a Divine preparation for Christ to come “in the fullness of time” and make the Blessed Trinity Who is God Himself, known by the power of His own self-sacrificing self-forgetting Love. So to reveal something in OT times which makes sense only in the light of the Love of the Father & the Son and the Spirit, and the clue to which is Christ Himself, would have required the Jews to have had a faith different from what they did. ISTM anyway.

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