4:12- John

Looking at the cross-references in my bible- this verse is quoted at least three other times in the New Testament. In John as an editorial comment explaining why, when he had done so many signs in their presence, that people did not believe in him. Of the verse, John says- “Isaiah said this because he saw his glory and spoke about him.”

Is this a case of a New Testament author using the Old Testament in a not particularly obvious to our eyes Christological way? It doesn't read to me as though Isaiah is talking about Jesus or looking forward to him when he writes these words. Although, if I was in Isaiah's shoes I'm not sure what I would be thinking- that's a pretty amazing vision to have- It's pretty glorious- God in the temple, with the hem of his robe filling it, seraphs flying around and calling out- holy, holy, holy is the Lord of hosts, the whole earth is full of his glory- then, bang, cue the smoke machine.
But John, I don't think is talking about Isaiah beholding the obvious here- God's awesomeness right in front of him, More he somehow saw into the future and saw Jesus, perhaps the crucifixion? (this is Jesus glory isn't it?) and spoke about the unbelief of Israel in the face of this.

It does fit, in terms of the sweep of the story, It's just that Isaiah doesn't really read that way, I think.