The Old Testament is a collection of writings whose period of origin spans over 1000 years. We are therefore dealing with historical writings that stretch from the late Bronze Age to the time of the Roman Republic. This observation alone makes it clear why we cannot be dealing with a culturally or religiously uniform work in the Old Testament. Unless, and this is where the question comes in, a redactor had taken the red pencil and created a unity. But why did this not happen - at least to the extent one might expect?

From my point of view, several aspects must be addressed in this context, all of which are related to one question, namely the question of how the individual writings of the OT want to be understood or were ultimately understood by their "ancient" readers and thus also possible editors.

While both questions are not so easily answered in a nutshell, the ancient tradition of hermeneutics (ἑρμηνεύειν hermēneúein) at least gives us some insight in relation to the latter of the questions. The word hermeneutics derives from the Greek verb hermeneuein (ἑρμηνεύειν), which itself has many meanings. In particular, its semantic aspects "to understand", "to explain" and "to translate" had an effect on the formation of concepts. Already in antiquity, the verb hermeneuein was associated with the name of Hermes, the messenger of the gods, to indicate the aspect of a communicative mediation of divine and human reality. Or to put it another way: hermeneutics is always about trying to understand the actual and deeper meaning of a text (or a thing); to grasp reality! Often associated with this is the idea of a multiple sense of writing, that is, the idea that a text has multiple levels of information that go beyond simple reading (or listening). This kind of textual understanding is found throughout antiquity in Jewish texts, be it, for example, the Letter of Aristeas with its moral justification of the Old Testament food laws ("But as for the forbidden birds, you will find that they are wild and carnivorous and rape (sic!) the rest with their strength. They also feed unjustly on the above-mentioned tame birds..."), the writings of Philo of Alexandria or, finally, the rabbinic interpretations starting from the end of the 2nd century A.D. Such interpretations, which are also often accompanied by "corrections" and changes, are ultimately even reflected in the magnificent murals of the fascinating synagogue of Dura Europos; they thus had a place in the everyday Jewish communities.

But even in the Old Testament itself there are passages (e.g. Hos 12) that interpret other Old Testament narratives and "correct" them within this framework. Nehemiah 8:8 even tells us of such an interpretation in the context of the first recorded "word service" (Wortgottesdienst): "They read from the Book of the Law of God, making it clear and giving the meaning so that the people understood what was being read." The Targum literature (Aramaic: 'interpretation, translation, version') of Judaism is precisely such interpretations in written form, whereby the Targumim in part expand biblical narratives considerably in content! But both Nehemiah and the Targum literature make one crucial thing clear: there is a point in Israel's religious tradition when amendments or the addition of explanations to traditional texts is no longer tolerated, because the texts at hand are perceived as sacred and unchangeable. The explanations etc. must therefore be made verbatim in external writings (e.g. Targumim) or in worship. What applies to the period of Nehemiah, however, also applies in a similar form to the editors and schools of scribes before: although certain editors (e.g. Elohist, Jahwist, Priestly or also Deuteronomic) make changes and adaptations to the texts before them, they too already have texts before them that have sprung from long religious traditions and where they seem to shy away from making arbitrary changes or deletions. For example, the Deuteromist school (DtrG) takes the theological position that there is only one God and one proper place of worship, Jerusalem. Nevertheless, the stories about the altars of Abraham are no more erased from the OT than the visit of Elijah to Bethel (where one of the temples of the Northern Kingdom was located - thus a "wrong place" of worship in the view of the DtrG), even if in the latter case the temple and thus the probable reason for Elijah's visit is concealed (or possibly erased).

The answer to the question is therefore: The editors of the collection of scriptures we call the Old Testament had, on the one hand, a different understanding of scripture or, to put it even more radically, a different understanding of reality. In their eyes, the texts were equivocal (not to be confused with arbitrary) and proclaimed truth, even if this truth did not necessarily have to be historical. Consequently, there was no need to draw a straightforward history or clear theology. The diversity of the texts was perceived as a richness, not a weakness. An occurrence that we encounter again, for example, in the New Testament in the Gospels. The question of whether a biblical narrative is historically true is therefore not relevant to the self-understanding of Israel's traditions. On the other hand, even the first editors were confronted with texts of faith that had enough relevance for them to be handed down, but in the same breath, of course, made the claim not to be simply changed or smoothed over. Today's final form of the Old Testament clearly shows in numerous places which middle paths the editors took in order to do justice on the one hand to the theology and needs of their time, but also to the spiritual heritage of their ancestors.

As some have probably noticed, I have not gone into the first section of the question - the introduction. The reason for this is quite simple: some things are mixed up here, e.g. the development of Israel's image of God with the origin and redaction of the biblical texts, which are not initially drawn together in research in this way. The development of the image of God is a subject area in itself (and one that is to a large extent already completed at the time of the writing of the biblical texts), so I will only refer to two books at this point, for those who are interested:

Mark S. Smith: The Early History of God. Yahweh and the Other Deitries in Ancient Israel, Cambridge, 2002. and Reinhard Müller: Jahweh als Wettergott. Studien zur althebräischen Kultlyrik anhand ausgewählter Psalme, Berlin 2008 (= Beihefte zur Zeitschrift für die alttestamentliche Wissenschaft, Vol. 387) translated: Yahweh as weather god. Studies on ancient Hebrew cult poetry based on selected psalms, Berlin 2008 (= Supplement to the Journal for Old Testament Science, Vol. 387)