Wonderment:
Of the languages I have studied beside English, Greek is far down the list. More of an analyst with a dictionary and grammar than someone with any type of fluency. So I will concede to all that I am not able to argue this matter from a standpoint of grammar much beyond the rudimentary. But all the same, I am not arguing this matter because I am that much more naturally comfortable with notions such as a triune God. My case is simply what I read in the text of John and what, evidently, early church writers saw in the text as well speaking in the same tongue. They appear to spell it out.
It was pointed out elsewhere as well that if Jesus simply asserted that he existed in some form prior to birth, he was not necessarily evoking an idea that was blasphemy. Many, including the Jews of the time, have suggested that we have some existence prior to birth. And the duration of this might have been a speculation as well, an existence that could have extended prior to the time of Abraham - though it seems like a stretch as well for it to come up as a rejoinder in such a context.
But what clearly provoked the rage in Chist's listeners was his choice of words.
Significantly, Origen in breaking all this down does not refer to the Holy Spirit, but simply the Father and Son.He does not suggest that Jesus was the Archangel Michael or a spirit older than Methuselah.
And in the case of Chrysostoms:
"But wherefore said He not, “Before Abraham was, I was,” instead of “I Am”? As the Father uses this expression, “I Am,” so also does Christ; for it signifies continuous Being, irrespective of all time. On which account the expression seemed to them to be blasphemous. Now if they could not bear the comparison with Abraham, although this was but a trifling one, had He continually made Himself equal to the Father, would they ever have ceased casting stones at Him?"
If you believe that this quote is somehow carefully edited to convey such an idea, then perhaps someone can provide us with an alternate translation of what the first sentence of the quote above must have said.