In hermeneutics, is there a special term for the reason a book in the Bible, or even a chapter within a book, was written? Perhaps the special term would be in Latin or in Greek. For example, "The ______ of the Gospel of John is to tell unbelievers about the Son of God, Jesus Christ, so that by believing in Him they would have eternal life."
There is no particular reason to shy away from the rhetorical aspects of the contents of the Bible. Yes, I'm a rhetorician (i.e., an expert in rhetoric), but any ol' Christian or Jew can appreciate any one or more of the following concepts:
By this, I mean there might be a central idea or theme. The book of Joshua, for example, details the entering and possessing of the land of promise (Canaan) by Israel, under the leadership of Moses' successor, Joshua. Although Joshua does not state the thesis explicitly, we can surmise fairly that his thesis could be: "God promised through Moses that God would give them every square inch of the land of Canaan, and God fulfilled his promise miraculously when Israel walked by faith, believing
1) that no human power in the land of promise would be able to stand before them all their lives, once they entered the land by faith;
2) that God would never fail them or forsake them (Joshua 1:5-6);
3) that by being strong and courageous, they were simply trusting God to do what he promised to do, and in that trust their faith would sustain them; and
4) that complete and unwavering obedience to God's Law would lead to success wherever they might go (1:7)
I'm sure someone else could invent a less wordy thesis statement, and I certainly welcome all comers. The point is, every writing in Scripture has a thesis, a theme, and a point of view which are endued by the author(s).
Although Joshua may not have thought it at the time he wrote and/or compiled the book which bears his name, one of the purposes the Holy Spirit had in mind was to teach us today that we Christians are engaged in warfare, but a different kind of warfare. We do not war against "flesh and blood, but against the rulers, against the powers, against the world forces of this darkness, against the spiritual forces of wickedness in the heavenly places" (Ephesians 6:12).
Unlike Israel's "valiant warriors" (Joshua 6:2) who wore heavy body armor and carried swords and javelins, we Christians are to "take up the full armor of God"; namely, the breastplate of righteousness, shoes of the preparation of the gospel of peace, the shield of faith, the helmet of salvation, the sword of the Spirit, and prayer itself, which binds each piece of armor and weaponry together (6:13-18).
One more example might be in order: the book of Genesis, or the book of beginnings. How did the universe spring into existence? Genesis answers that question: "In the beginning, God created the heavens and the earth." How did human beings come into existence? Genesis answers that: God created out of His omnipotence and omniscience a critter who would forever be in his image, except on a much lower level!
How did the human race become a race of people instead of just one man and one woman? Genesis answers that. Throughout the book, Moses (yes, I assume he either wrote and/or edited most, if not all, of Genesis) says such things as,
In other words, Genesis answers questions about both creation writ large and the human race writ small, and it does so with the same or similar expressions. Why all the attention given to genealogies? Curt Sewell in his "The Tablet Theory of Genesis Authorship," cites the work of Professor of Assyriology D.J. Wiseman. In revising and updating his father's (P. J. Wiseman's) book on Genesis, D. J. Wiseman published the book “Ancient Records and the Structure of Genesis” (Nashville: Thomas Nelson, Inc., 1985). In his book, a collaboration of he and his father, he gives us an answer to the question "Why so many genealogies?":
". . . most of the old clay tablets found by [D. J. Wiseman's father, [P. J. Wiseman] had 'colophon phrases' at the end; these named the writer or owner of the tablet; they had words to identify the subject, and often some sort of dating phrase. If multiple tablets were involved, there were also 'catch-lines' to connect a tablet to its next in sequence. Many of these old records related to family histories and origins, which were evidently highly important to those ancient people. Wiseman noticed the similarity of many of these to the sections of the book of Genesis" [my italics].
Moreover, there is the element of a writer's
Paul's exigency regarding his church-plant in Corinth provides an example. The purpose of Paul's second (canonical) letter to the Corinthian believers in Corinth was to nip in the bud the undercutting of his God-given ministry by some folks in the congregation who did not like Paul, did not respect Paul, and did not accept (for whatever reasons) his ministry.
There was also the matter of the collection for the poor saints in Jerusalem, and the Corinthians were lagging behind in their collection and release of those funds.
And finally, we must not forget
The Nexus of Speaker (or Writer), Audience, and Occasion
These three kinds of speaking have existed from time immemorial, I imagine, and when a communicator engages an audience on a given occasion, there will always be in his or her communication an element of information, persuasion, and inspiration (the last of which takes us back to ancient Greece, and what they called the epideictic speech, which was a speech containing praise or blame).
I may have misunderstood your question, brilliant. Nevertheless, I hope my rather lengthy answer provides you with something useful. By the way, in your question was the word researched supposed to have been the word written, instead?
The technical terms you're looking for are:
These are, essentially, the author's own "preface" to the following work which orients readers to its leading themes and aims.
The much-cited study by B. A. van Groningen, "The Proems of the Iliad and the Odyssey" Mededeelingen der Koninklijke Nederlandsche Akademie van Wetenschappen n.s. 9/8 (1946): 279-294, offers these typical features of the proem:
along with a few other features. This terminology is also used in reference to the Midrashim (although admittedly in a specialized sense), as well as the New Testament and yet more widely in literary studies.
Thus, in OP's example, it would work this way:
There are several terms for this. I'll list them from most colloquial to most technical:
These are probably the main terms you'll come across nowadays.