It's a noble ideal, and done properly, I certainly have no objection to such an approach, for just as the prophets expanded on and explained the Torah, the NT expands on and explains the Torah, Nevi'im (Prophets), and K'tuvim (Writings)--the TaNaKh.
However, here's how not to interpret the Tanakh in the light of thet NT:
1) Become a Greek scholar without spending any time studying the Hebrew language, culture, and way of thinking.
2) Read the NT. Ignore the "Old."
3) Develop all of your theologies from the NT, preferably leaning on the writings of Paul. After all, 90% of all your sermons will be from Paul's letters.
4) Then, after you've come to all your conclusions (with a hefty dose of Protestant tradition to make sure you're acceptable to the mainstream), you can go back and actually study the OT. Not too much, mind--it's old and superceded by the New, after all.
5) When you come to an apparent conflict between the theology you developed reading the NT and something in the OT, don't change your theology--just ignore what you found in the OT and explain it away with the vague statement, "Well, all prophecy is fulfilled in Christ," or "Well, we're not under Law, so that doesn't matter."
There's a very basic problem with trying to develop theology solely or mostly from Sha'ul's letters: All of them, with the exception of Romans, were written in response to some crisis in the Church, a crisis to which we are not privy to all the details. So? you ask. Have you ever heard just one half of a phone conversation and misunderstood what was said as a result? Me too. So if we're only getting one-half of the conversation, Sha'ul's answers without knowing the exact question, might that cause us to misunderstand some of what he writes?
Yep.
Interestingly, when Sha'ul wrote his letters, I don't think he considered them Scripture, but rather simply midrash, commentary on the Scriptures--which he would have considered to be the Tanakh and (insofar as they were written and available) the Gospel accounts. That's not to say that we shouldn't regard them as Scripture today, but Sha'ul never wrote them to stand alone and so they can't be understood properly if you try to read them as stand-alone pieces. Rather, we should treat them as a divinely-inspired and divinely-correct commentary on the Tanakh and the Gospel. But just like we wouldn't encourage someone to read a commentary written today without reading the Scriptures first (or at the least, side-by-side), we shouldn't encourage the practice of reading the Pauline Letters without first reading and getting a grasp of the Tanakh and the Gospel accounts!
Kefa, or Peter if you prefer, was well-aware of this danger, as he wrote that "our beloved brother Paul also has written to you according to the wisdom given to him as also in all his letters, speaking in them of these things; in which are some things hard to be understood, which the unlearned and unstable pervert, as also they do the rest of the Scriptures, to their own destruction" (2 Pt. 3:15-16).
Let me give an example. Many read Romans 9 and take it to be a teaching of absolute personal predestination. They read, for example, v. 13, "Jacob have I loved, but Esau have I hated," and say, "See, God loves and hates people according to His own will even without them doing anything!" There's just one problem: That's not what the passage Sha'ul is quoting says.
To read Sha'ul's quote in context, Malachi 1:1-5 says,
The burden of the word of ADONAI to Israel by Malachi. "I have loved you," says ADONAI. But you say, "In what have You loved us?"It is obvious that Malachi was not speaking of the individual persons of Jacob and Esau, but of the nations that came from them, Israel and Edom. Yet because the Tanakh has been generally treated with contempt--"That's the Old Testament; we follow the New!"--many have failed to go back and actually read Sha'ul's quotation of it here (and elsewhere) in context in order to properly understand the point he was trying to make."Was not Esau Jacob's brother?" says ADONAI; "yet I loved Jacob, and I hated Esau and made his mountains a desolation, and his inheritance to be for the jackals of the wilderness. If Edom says, 'We are beaten down, but we will return and build the waste places.'"
So says ADONAI-Tzva'ot (the LORD of Hosts), "They shall build, but I will throw down; and they shall call them the region of wickedness, and the people with whom ADONAI is indignant forever. And your eyes shall see, and you shall say, ADONAI will be magnified beyond the border of Israel."
So yes, there is a very real sense in which the NT cannot be understood without reading it in the light of the Tanakh, just as the Tanakh cannot be fully understood without the New Covenant of the Messiah. That will threaten some dearly-held theologies and traditions--most especially in the related areas of ecclesiology, Israelology, and eschatology--but it is the plain truth.
I have looked in the scripture for clues on this subject. I feel that at least some of the authors of scripture knew that they were writing inspired words. John, writing the book of Revelation, should have suspected from the first verse.
I find it interesting that you quoted 2 Pt. 3:15-16, which I think suggests that Peter knew that Paul’s epistles were indeed scripture, He accused some, in his audience, of treating them like they treated other scripture. Why would this be a problem if they were not inspired?