Here we have a problem of the Christian bible creating a “prophecy” based on a mistranslation. Sh’mot / Exodus 3:13-14 does not say “I am.” Sh’mot / Exodus 3:13-14 says
“וַיֹּֽאמֶר אֱלֹהִים אֶל מֹשֶׁה אֶהְיֶה אֲשֶׁר אֶהְיֶה (“G-d said to Moses, ‘Ĕhyĕh ashĕr ĕhyĕh’...”).
G-d said to Moses אֶהְיֶה / Ĕhyĕh / “I will be” – not “I am.” "Ĕhyĕh" is the first person singular imperfect form -- it is not present tense (I am) - it is future (I will be).
Although G-d has many "names" in the T'nach, telling Moses that "I will be" is the identifying name that the Jews will believe is important. Why? Because G-d has used this before. In B'reshit / Genesis 26:3 G-d told Isaac " and I will be (וְאֶֽהְיֶ֥ה) with you and bless you, since it will be to you and your offspring that I will give all these lands."
G-d is repeating the promise He made, and it is by this promise His people will know Him.
G-d said to Moses אֶהְיֶה / Ĕhyĕh / “I will be” – not “I am.”
This is immediately followed by אֲשֶׁר אֶהְיֶה / ashĕr ĕhyĕh’ (“as I will be”).
I will be as I will be.
Let us put this in context – this is not so much G-d’s name as it is an answer to Moses’ question to G-d. Moses has asked G-d “'So I will go to the Israelites and say, 'Your fathers' G-d sent me to you.' They will immediately ask me what His name is. What shall I say to them?'” Sh’mot / Exodus 3:13.
Most people think that Moses’ asked G-d “what is your name?”
Moses said "They will immediately ask me"
What do I tell the people?
G-d does not give a name by which He is known – both Moses and the Jews are familiar with various names for Him. Gd- is known by many names. Each Divine name is descriptive and highlights a specific Divine trait or attribute.
Moses is not asking for a “handle”, but rather he is asking what can I tell the people so they will believe me – that you sent me? How will they know I am telling the truth? The Torah has many "names" (truly more ways of defining His actions than a "name") and each "name" represents a way people perceive Him in a given situation. When we see His mercy He is called HaShem (or "my L-rd" or "my master" -- from the word אָדוֹן / "adon." When He sits in judgment as a powerful ruler / judge we call him by the word אֱלֹהִים / elohim -- a word used to speak of powerful humans, angels, G-d and even false gods. There are actually man such "names" for G-d in the T'nach -- but when Moses asked G-d "what do I tell the people?" G-d replies not with a name, but with the statement:
“כֹּה תֹאמַר לִבְנֵי יִשְׂרָאֵל אֶהְיֶה שְׁלָחַֽנִי אֲלֵיכֶם / “this is what you are to tell the children of Israel —‘ אֶהְיֶה / Ĕhyĕh / 'I Will Be sent me to you.'”
Why would G-d identify Himself using such an ambiguous, non-nondescript name? A name that denotes the future (I will be) – not the present (I am)? Even more strange, this “name” is actually a verb not a noun. The verb is in the imperfect, future tense (hence “I will be”).
The great Torah commentator Rashi explains: “I, the G-d who has been with them throughout their enslavement by the Egyptians, will continue to be with them throughout all the other enslavements and persecutions that they are going to suffer at the hands of many other conquerors”.
Now, let us visit the Christian text which purports to “fulfill” the statement that G-d will be with the Jewish people.
John 4:26 is actually the answer to a question in John 4:25 “The woman said, “I know that Messiah is coming. When he comes, he will explain everything to us.” Then Jesus declared, “I, the one speaking to you—I am he.” John 4:25-26.
Ergo, this passage is not a prophetic fulfillment that Jesus is G-d -- the great “I am.” Jesus is asked if he is the messiah and he says that he is the messiah (not G-d). Of course we know that Jesus was not the messiah either, but for the purposes of this particular “prophecy fulfilled” claim by the list maker it is proven false. Jesus is not claiming to be G-d in John 4:26. It is not a fulfillment of Sh’mot / Exodus 3:13-14 (which is not a prophecy).
John 4:26 does not make any claims that Jesus is G-d, ergo this supposed prophecy fulfilled by Jesus is false.
There is a Midrash (story meant to make a moral point) which tells us that G-d said to Moses "I shall be with them in this sorrow (Egyptian slavery) as I will be with them in other sorrows." Moses told G-d "An evil in its own time is enough!" In other words, why should G-d imply to the Jews in slavery that there would be future sorrows -- future exiles? G-d then told Moses to simply say to the Jews "I shall be (with them in this sorrow) has sent me."
"I will be as I will be" means that G-d is unchanging, He will be always as He is, and He will always be with His people, the Jewish nation.