To Jews and Christians mostly but others are free to poke their noses in....
What is the Messiah meant to do, according to Tanakh?
No 'NT' quotes thanks.
Greetings Rival,
The problem you have with this question is the starting point. First, the minute that you use the English word "messiah" as a translation for the Hebrew word (משיח) when in reality your question is about a Davidic king you essentially have made it impossible for you to get answers that really address your question.
As you know, the closest thing in the Hebrew language to what the word "messiah" often means to English speakers, due to the Christian influence on the English language, would be (מושיע) or (גואל) neither of which still don't mean what most English assign to the word "messiah;" again due to the Christian influence on these type of English words.
Second, the minute you use the english word "messiah" with a capital "M" the question you have will go completely off the rails right into a question that is,
"What do Christians mean by messiah, according to the Greek inspired, Christian bible, using the New Testament as the "Oral LXX" for said text."
I know this is not what you were asking, humor me a bit, but that is exactly where the question leads, as it is written. One of the reasons I state this is, if you have noticed, every Christian answer that you have been given is from the NT thus far in this thread, and others most likely.
As you already know, for Tanakh (in Hebrew) based Jews, there are no capital letters. So, there is no a real difference between the title of a (משיח) who is a Kohen a (משיח) who is a ANY king of Israel who had oil poured them like Shaul, like David, etc, or a (משיח) future Davidic king. Capitalizing the first letter in English, when Hebrew has no capitals, and even using a word that is foreign to the question, like "messiah" is, skews the discussion right into New Testament terroritory.
That being said, a better question for Torah based Jews would be,
"What does the Hebrew Tanakh, w/o English translation, state about the future Davidic king? Feel free to use native ancient Jewish nuances, words, definitions, concepts, etc. to explain it."
Both Jews and Christians see the Tanakh as holy and that some parts describe the Messiah. I'm asking about the Tanakh specifically to see how their understandings became so radically different while adhering to the same scriptures.
This is the next issue. The reality is that Jews and Christians don't see the Tanakh the same way. Most Christians don't even possess what can be defined by Jews as a Tanakh, a term that for the most part they [Christians] don't even use to define the Christian bible either historically or modernly. I.e. For Jews, in reality, a Tanakh is something that looks like the below:
You find a a Tanakh in Hebrew in way more Jewish homes than you will Christian homes. For Christians, the above books in Heberw don't really mean anything and only have importance for a small minotority of their scholars. For them, what has value is mostly the English translations of their own Christian bible, and only when it relates back to something from the New Testament.
In terms of your question,
"how their understandings became so radically different while adhering to the same scriptures."
That is an easy one to answer, w/o a lot explaination needed. The early Jewish Christians had an agenda, no different than the Ebionites, the Sadducees, the Essenes, the Northern Israel king Ahhav and his wife Izevel, the Giv'onim, Korach, the Mixed Multitude who were led by former advisors to Pharoah who led the building of the golden calf, and Lot - the nephew of Avraham. Thus, they had to create different understandings to try and convince themselves, and at times others, that they were right, even when it flew in the face of reality.
These are a few examples of those who had agendas and decided to take a path that seperated themselves from Am Yisrael and the mitzvoth that Hashem gave. In each situation their movements eventually died out as
"identifiable Torah based leaders/scholars/etc.," and thus the proof that their concepts did not come from Hashem. This includes the original
Jewish Christians, even though most of them were not leaders or scholars in the Jewish community. This is one of about three reasons the Jewish Christians died out about 2 generations after their start, something even alluded to by the NT author of jude 1:4. i.e. the author of that text seems to point out that between the 1st and 2nd generation the original Jewish Christians were having "membershp" issues. Further, if the NT authors can be believed about something, which is a stretch, it is most likely true that the early Christians did leave their families behind and not start new ones. Probably out of the beleif that the end was near and thus they sealed their own historical and theological fate.
The non-Jewish Christians, who took what was left when the Jewish Christians disappeared off the historical map, tried to come up with something "new" and "different" thus they HAD to seperate themselves conceptially even further from anything that was Jewish. Quoting one or two lines, in Greek, out of context, while ignoring everthing else in the original text, etc. is a non-Torah based method of making a
"definative claim" about the text and it this is the path that early Christianity took. Thus, making the lack of connection complete. Further, the idea of rank and file Christians reading the Christian bible for themselves is a bit of a new idea/new reality - most average Christians weren't reading the NT for themselves prior to about 600 years ago; let alone reading it in Greek. One of the consequences has been some of them leaving and in some situations converting to Judaism.
Why Christians Were Denied Access to Their Bible for 1,000 Years By Bernard Starr, Contributor College Professor (Emeritus, City University of N.Y),psychologist, journalist.
In reality, Jews and Christians don't adhere to the same "scriptures." Even that word, doesn't mean the same thing for Jews as it does for Christians.
Note: Just consider what Jewish sources say the purpose of the nach writings are, and what will be done with them when a Torah based nation is re-established. Thus, Jews and Christians don't carry the same background with how one determines what is accurate, aunthentic, and authoratitive.
Here is a way to test what I am saying. Have a Jew read from the below section of Yeshayahu (in Hebrew) that was found in the dead sea area. Then have a Christian read from it and ask them to point out how they determined where to start and stop quoting for their ideas. You will literally know the answer to your question within seconds.