The truth is we cannot know when a biblical writer is recording their own beliefs about God or somehow God has communicated what exactly to write down from God. How would that work anyway? Did God really direct “Now go, attack the Amalekites…put to death men and women, children and infants, cattle, sheep, camels, and donkeys” (I Sam. 15:3), or was that the writer’s understanding of God at that time?
Sometimes there may be plausible explanations to OT passages that contradict the view of God in the NT, but the solution may not be to always rationalize confusing passages. We know God didn’t verbally dictate the entire Bible. We simply cannot be certain when God did or didn’t allow the writers the freedom to misunderstand and grow in their understandings of God. God has proven to not be controlling by accepting decisions made contrary to God’s wishes.
Insisting the Bible is somehow magically infallible often leads to not acknowledging that an author’s meaning in ancient literature is always subject to interpretation thus error. Clearly, different opinions of the same biblical passage exist. God-breathed (2 Tim. 3:16), which could only mean the OT since the NT had not been formed when Timothy was written, can mean God intended the Bible for reflection upon what God is really like with the help of the Spirit (Jn. 14:16).
Oh, so everyone’s opinion is right!
Some interpretations are clearly wrong. God, unlike religious extremists, would never violate one’s freedom to force belief in God. Certainty often leads to dogmatism and unloving behaviors. The presence of universal moral sensitivities, suggesting the existence of a personal Creator, provide enough certainty. We may be better off without the Bible when used as a rules book rather than consideration for wisdom depending on individual circumstances.
How can we interpret difficult OT passages if we don’t think a moral explanation exist?
We can interpret all of Scriptures through the voice of Jesus and the lens of the Cross. Most biblical scholars accept the Gospels were written within at least 40-60 years when Jesus lived, so eyewitnesses could dispute claims made. I would consider Jesus’ view when your understanding of an OT passage contradicts what you believe Jesus taught and lived out. What kind of person who claims to be God sacrifices their life, when they have the power to prevent it, to convince others that God loves and desires to help us be the kind of person we want to be deep down.