Trinitarians and Modalists would often trot out John 8:58(in a matter of fact way) as evidence for their respective (and opposing) doctrines. By way of a reminder the KJV renders the verse: "Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am." Now mind you, a mere four verses earlier Jesus declares :"Jesus answered, If I honour myself, my honour is nothing: it is my Father that honoureth me; of whom ye say, that he is your God:" thus Trinitarians affected by logic ought to be wondering ,why if he and his Father are equal in every way, would being glorified by his Father make a difference and Modalists whose brains had not yet been devoured by the absurdity that is their dogma would wonder why the glory of their God seems to fluctuate from mode to mode.
Nevertheless one might sincerely wonder what in John 8 verse 58 would qualify as evidence that the one God of the bible consists of three persons and that the Lord Jesus Christ is indeed one of these three persons. Well according to proponents this view the Greek 'ego eimi' rendered 'I am' in many translations is supposedly a title for almighty God. Now ,let us suppose that there is some substance to this claim (spoiler alert; there isn't) how does one sensibly extrapolate the necessary implication of a triune deity from this fact or for that matter that the Lord Jesus is a mode of the supreme being? Jesus is not the first Messiah of almighty God to share titles held by God.
Exodus7:1KJV"1And the LORD said unto Moses, See, I have made thee a god to Pharaoh: and Aaron thy brother shall be thy prophet."
Here Moses is called Theos/Elohim by the Lord JEHOVAH himself, as I have repeatedly demonstrated there is more trinitarian style evidence for Moses' Godhood than Jesus' Godhood. But from where did this notion that 'ego eimi' is a divine title originate. Supposedly from it's use at exodus3:14. The trouble is that if one examines the Septuagint version ,which would have been the text available to Jesus' contemporaries, one would note that 'ego eimi' is not used as a title. In fact in response to Moses' inquiry re:JEHOVAH'S name God responds "ego eimi' ho on" i.e "I am the being" and at Exodus 3:14c is instructed to tell the Israelites that "ho on" i.e the being had sent him. Clearly none of this is a declaration of a name or title but a statement of intent re:the captive condition of his people. Despite appearances he was the real God not the idols of the Egyptians and he was about to demonstrate that beyond all reasonable doubt.
As for the name by which he is to be invoked in prayer and otherwise :
Exodus3:15ASV"And God said moreover unto Moses, Thus shalt thou say unto the children of Israel, JEHOVAH, the God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob, hath sent me unto you: this is my name forever, and this is my memorial unto all generations. " The same name by which their ancestors invoked him. Even if one wanted to make reach that a divine title was being declared, " ho on" would be this title not "ego eimi" . Interestingly at revelation 1:4 and 1:8 the God and Father of Jesus is indeed referred to as " ho on" in the Greek text.