Here is yet another Biblical proof that Jesus of the New Covenant is Yahweh of the Old Covenant. In John 12 we read: “But though he had done so many miracles before them, yet they believed not on him: That the saying of Esaias the prophet might be fulfilled, which he spake, Lord, who hath believed our report? and to whom hath the arm of the Lord been revealed? Therefore they could not believe, because that Esaias said again, He hath blinded their eyes, and hardened their heart; that they should not see with their eyes, nor understand with their heart, and be converted, and I should heal them. These things said Esaias, when he saw his glory, and spake of him” (John 12:37-41).
Although Jesus had performed multiple miracles, John tells us that the people did not believe on Him. John proceeds to quote several Isaianic passages. The first one is from Isaiah 53, from among the most precious Messianic chapters: “Who hath believed our report? and to whom is the arm of the LORD revealed?” (Isaiah 53:1). John continues to quote Isaiah: “Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they see with their eyes, and hear with their ears, and understand with their heart, and convert, and be healed” (Isaiah 6:10).
Now comes the connecting Scripture that is of particular interest to us: “These things said Esaias, when he saw his glory, and spake of him” (John 12:41). In other words, when Isaiah saw His, or Jehovah’s, glory. This takes us right back to Isaiah 6, when indeed Isaiah saw Jehovah. I have substituted the word Jehovah for the Hebrew equivalent of LORD in all caps, יְהוָה, and Adonai for the Hebrew equivalent of Lord with the first letter in caps, אֶת־אֲדֹנָי.
“In the year that king Uzziah died I saw also ADONAI (the Lord) sitting upon a throne, high and lifted up, and his train filled the temple. Above it stood the seraphim: each one had six wings; with twain he covered his face, and with twain he covered his feet, and with twain he did fly. And one cried unto another, and said, Holy, holy, holy, is JEHOVAH (the LORD) of hosts: the whole earth is full of his glory. And the posts of the door moved at the voice of him that cried, and the house was filled with smoke. Then said I, Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips: for mine eyes have seen the King, JEHOVAH (the LORD) of hosts.” (Isaiah 6:1-5). The sacred symbolism of the Sacrament follows these verses of Isaiah.
But let us return to our verse in question. It is clear that Isaiah had seen the King Jehovah of Hosts, יְהוָה צְבָאוֹת מְלֹא, in His glory. John so testifies of this, explaining that Isaiah had seen Jesus the Christ in His glory.