I am not a biblical scholar, but I have a read some things and thought a lot about the brutality and violence in the Old Testatment.
Here are my thoghts and how I have tried to expain it to my adult children who are, in order: one semi-spiritual but not religious, one agnostic, and one self-identifying as a Christian but not in any traditional way; all are progressives who find the OT a bit repulsive.
The Old Testament, in my understanding, is a collection of documents that basically say to he Hebrews and the surrounding cultures (of which they were ancestorally related to, although of a different tribe) that our tribal God, Yaweh, is greater than your tribal god (Molech, Baal, etc) and therefore you should follow our God. And/or reminding the Israelites themselves, WE need to keep following OUR God and not those of our neighbors.
The style of Hebrew in which the Pentateuch is written, I have read, is far younger than the events it reports. Likewise, the historical books as well. Many OT books, it seems, were edited, written or compiled after the return from Babylon in an attempt to expain that traumatic experience for the Hebrew people.
Going back to Moses commands to the Israelites and the accounts in Joshua regarding the Promised Land, no doubt there were some tribal battles and skirmishes over land when the Hebrews returned from captivity in Egypt, but even the OT iself reports that they "failed" to exterminate all the Caananites in the land. So other than several pitched land acquisition battles reported in the OT, they likely just kind of settled in and shared space and legitimaized it through intermarriage or sort of pushed the other guys (who were thier distant cousins anyway) out because they were more powerful and numerous. The stories recounting this were passed down in the form of "our God is better than yours" and we utterly defeated you - which just isn't true: we defeated some of you, we assimilated some of you and we kind pushed the rest of you out, or at least to the fringes and least desirable areas. But in telling our stories and later writing them down we now "recollect" that we crushed you guys (or, like recounting the size of a fish that a recreational fisherman caught: it was thiiiiiiiiiiiiiiiis big; thus, we aniahlated those Caaanites!). But, again this is just my conclusion from my reading and thiking about this. Looking at both the internal evidence of the OT and the external archaeological evidence, they didn't genicidally wipe out the Caaananites.
Were they commanded to commit genocide by God? It's doubtful. Who knows? Probably not, but they recorded their national story in a triumphalistic manner that was part of the literary construct of the day, in which our God beat the crap out of your God and we beat the crap out of you and we won!
As "scripture" God allowed them to record the story this way because it was the manner that was coherent and assumed at the time the stories took shape and also at the time the stories were written down.
As for stoning disobedient children and all those laws, it is doubtful the Hebrews ever followed those literally. Look King David with his son Absolom. He led a revolution against his father and David did NOT want him killed in battle and wept over his son's death in Absolom's ultimate defeat (again, internal evidence that they didn't really follow this stuff).
Nor do we really follow the "stuff" either that we read in the New Testatment. If we all who had two coats (probably a lot more) gave the second one to the person who has none and lived with just one coat, the modern economy based on economic growth through production, sales, exports and consumer acquisition, would come to a screeching halt and there would be permanent recession. We are selective, take things with a grain of salt, or spiritualize the meaning.
Next angle to consider:
I think God's relation to sinners has always been merciful.
Did a guy get struck down for trying to balance the Ark? Maybe? Maybe with a different mindset of the people then, God had to do that to get their atttention and make his point. My belief is that if He did have to do that, that incident was that fellow's immediate toll house or purgatory (or even martyrdom), however you want to understand it.
To my mind, a more likely scenario is that a real guy had a heart attack or something (between his religious exuberance and trying to steady a heavy Ark), died in the process and the story was interpreted a certain way as "don't mess with Yaweh". Or, even more likely, the event never happened and this story was just one the the literary conventions of the time and people understood it as such, just as we understand parables (there wasn't a real vineyard owner who sent emisaries to collect rent who were all mistreated, so that he sent his son, who they killed; it is a parable recapping the prophets ministy and foretelling Jesus' impending death). Likewise this is a story of how holy Yaweh is, set up to reinforce the unique position in society of the priestly cast. It doesn't make the message un-true nor should undermine our trust in the Bible. It's just that WE read the story AS IF it was a contemporary newspaper account of an event and it wasn't written that way or intended to be understood that way. The fact that we read it wrong doesn't undermine the truth of what it is trying to teach us and it doesn't mean writers were making up stuff they knew to be false just to make a point (like a propagandist). They were telling stories in literary conventions everyone was familiar with and they all "got" it; just like we "get" the parables.
But there are numerous accounts of God's mercy that are just as obvious and tender in the OT as in the New: Hezekiah (his prayer of repentance); Kind David (also left us with a wondeful prayer of repentance); the mercy of God shown to Sarah and to Anna (much like the mercy shown to Elizabeth in the gospels, not to mention how Tradition indicates the same mercy to the parents of the Theotokos!).
The psalms are full of the mercy of God (although they are very human as well and there a several very vindictive, troubling ones as well).
The minor prophets show a very merciful God toward the poor and oppressed (also something that we conveniently overlook today).
What of the exodus, the plagues and killing of the first-born Egyptians? Obviously, Yaweh, through Moses, performed some pretty serious feats to get the Pharoah's attention and to make the Egyptian people want the Israelites to get the heck out of their land. And some miraculous path through a waterway blocking the Hebrews escape was opened to them by God and God protected them by allowing the waters to close over behind them. Did the whole Egyptian army pursuing them perish and drown? Who knows?
All I can say is that I believe God, in His love, comes to each generation and culture in terms and ways that they can understand and that, having demonstrated His extravagant love for humankind in the Incarnation and in the Passion and resurection of Christ, His love for humanity must have been the same prior to that inbreaking of God into humanity and remains the same since.
I also believe that the findings of modern biblical scholarship are some of those very tools and ways that God comes to us in the early 21st Century* and communicates His love to us so that we are given means to understand some of the cultural things in the Bible that are utterly foreign to us and perhaps repulsive to people who have been formed by 2,000 years of the Christian message of the love of God.
Those tools and findings of modern biblical studies have been found too threatening by people who read the Bible a certain way as a scientific and historical textbook (by modern standards) and therefore their OT God is very frightening to most of us. The same tools and findings have been interpreted by others, pressing the same modern standards of science, cosmology and historiography onto the Bible, to doubt the Bible's authenticity altogether and therefore dismiss it as a divine message from God to humanity.
I think both of those fundamentalist/modernist options are flawed and the Orthodox approach to Scripture can avoid either error!
*What I mean by this is, for example, the pre-exile Jews read the OT in a different way than the post-exile Jews; the Jews of Jesus' day read it different than in the days of Nehemiah; the early Christians read it in a different way than the Jews; the Church Fathers had different ways of reading the OT even among themselves - there was the Alexandrian school of thought and the Antiochian school of thought, no doubt influenced by the part of the Empire and cutural milieu of their region for example.
Once the canon of scripture was established there were still many interpretive methods through time whereby people could appropriate the message and meaning of the Bible to themselves in catagories of thought that led them to an encounter with God within their own time and place: philosophical (interacting with Greek philosophy) allegorical, symbolic, mystical, scholasticism (not very popular with Orthodox Christians, granted); spiritualized meaning; geocentric cosmology, then heliocentric cosmology, Dante's inferno (with various levels of hell), etc. etc.
This is just one layperson's take on the original post.
I am sure there will be many different opinions and I look forward to reading them.