How unified is the Bible text?
At one extreme, you could argue that, since the whole text is inspired by God and since He knew from the beginning what text He would inspire and how it would and should be arranged, then the whole Bible — including every book, Old and New Testament alike — should be treated as a completely unified text, just as if it had been written all at once by one author.
On the other hand, you could argue that, while the originals of each book (and the separate parts thereof) were inspired by God, allowances must be made for the fact that the authors were human, as were the translators and caretakers of the text, and that all these humans were separated in their work by centuries, indeed millennia, and so it is a mistake to interpret a phrase in, say, James as being foreshadowed by, say, a phrase in Ruth in the way that a novelist might foreshadow something in an early chapter that happens in a later chapter.
Or you could take a view somewhere along a continuum between these two positions. For example, one might follow the second approach while also bearing in mind that, not only did God know what He inspired into the Old Testament when He was inspiring what was in the New Testament, but often the writers of the New Testament were themselves consciously aware of what was said in that earlier inspiration. (There’s also the special case of the Old Testament prophets predicting details in the birth and death of Jesus Christ that came true.)
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An overarching point I would make is that we really don’t know for sure the right answer, and so I’d be wary about any approach whereby interpretation X of some important passage would be flat-out ~X if that approach is not taken. It’s fun and often fruitful to speculate about how the different parts of the Bible fit together, but let’s not distort a passage in order to cover seams or create foreshadowings. As I wrote elsewhere on this blogsite, “[F]inding evidence of the Gospel in every Old Testament passage can, no doubt, be done, but it starts sounding like the father in the movie My Big Fat Greek Wedding, who finds a Greek root in every word, whether there really is one or not.”
We should also bear in mind that the most important biblical unity is that it is all true, and this kind of unity is generally rather straightforward. Historians who tell the truth about what happened in year 2217 B.C. and later on tell the truth about what happened in year A.D. 33 don’t have to strain to achieve a unity of truth if they simply tell it like it was. Likewise, if God wants us to love Him and each other, and all his statutes are derivative of this, then a unified text is likewise not aiming at a moving target. Examples of how we should pray, beautiful poetry, the ultimate power and triumph of God over Satan — it’s not obvious how any of this presents a difficult juggling act.
Of course, one can define unity to require more than just noncontradiction and consistency: There must be a coherence and harmony in the text as well.
Fair enough, and I think that this coherence and harmony is certainly there, though it is hard to claim that the Bible’s variety of genres, authors, and time periods are indivisible, and that there are no disjunctions. Indeed, when you consider that, despite this variety, the Bible nonetheless tells one story of God, what He wants from us, and how He has worked to achieve His ends — well, it’s rather astonishingly unified when you think about it.
What’s more, the multimedia are part of the message: Without the variety of genres, authors, and time periods, the underlying consistency in the message would not be as dramatic. And it is important that the Bible reflect the different ways that God can inspire individuals and work through them.
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And what about more specific themes and storylines? Of course there is much in the New Testament that references the Old Testament, but to what extent does the OT explicitly foreshadow the NT? To give perhaps the most obvious example, is Abraham’s near-sacrifice of Isaac intended to foretell God’s sacrifice of His only Son?
In the course of answering a question like this, we must ask also did the OT mean something different for those who did not have the NT — that is, did its meaning change somehow as events unfolded? I think that “become clearer” is a better phrase than “change” in that last sentence — and that this after all is often the case with unfolding events, even those less dramatic than those in the NT. I think there are limits on how wholesale our reinterpretation of the OT in light of the NT should be, and that generally it is better to say we are adding layers of meaning rather than changing meaning. That is, for example, in the OT standing alone the Abraham/Isaac story tells us such-and-such, but now with the NT added it also tells us something new in addition to that.
We have to bear in mind, after all, that the Old Testament existed as inspired Scripture that God wanted to guide people for hundreds of years before the New Testament was written. Those people had to read and interpret the OT without having the NT, so it cannot be that the OT’s meaning without the NT is faulty. It may be incomplete, it may not be as rich and layered, but it is not, was not wrong.
But it is also true that the events in and around Galilee and Jerusalem in the first third of the first century, and the Scripture that was written about those events, can illuminate dramatically earlier Scripture. As a general matter, what is astonishing about the New Testament is how consistent it is with the Old Testament, and how it does not contradict it but, rather, deepens and intensifies its message.
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Footnote: On the specific question of OT statutes, I discuss in another post on this blogsite how the NT acts as a “pocket part,” sometimes superseding them.
Another footnote: Job is probably the oldest of the Old Testament texts, and in it the eponymous character declares, “I know that my Redeemer liveth, and that He shall stand at the latter day upon the earth” (Job 19:25), which is confirmed in the last book of the New Testament. So, yeah, there would appear to be some unity in the Bible’s text.