Here is the master key to rightly understanding the destructive "wrath of God" so rampant and widespread in the Old Testament.
The Old Testament uses the term "the wrath of God" to describe what the New Testament calls "the works of Satan."
Their problem was one of definition and differentiation. The Old Testament saints had a largely UNDIFFERENTIATED view of God and Satan. They believed Satan was God's "left hand," His "angry voice," His official "minister of wrath, His obedient "death angel" who always was just carrying out the Lord's express orders.
Old Testament saints wrongly included Satan in their "functional" definition of God. Whenever there was temptation, destruction, wrath, and death, all activities which the New Testament would later assign to Satan, the Old Testament would instead attribute these destructions to God Himself. They would not pray against the wiles of the devil, the way the New Testament instructs, but would rather beg God to stay His own wrathful hand. Satan was nowhere in their causative equation. God was the ONLY cause of both good and evil.
The New Testament, by contrast, better DIFFERENTIATES the identities of God and Satan. What is joined at the conceptual hip in the Old Testament is gradually separated and severed in the New. Jesus, it could be argued, IS the DYNAMIC DIFFERENTIATION of God's image from Satan's image. He is the refining fire which burns all the unworthy attributes the Old Testament God out and away from the pure and perfect divine nature.
So, when we see the Old Testament appears to say "by the letter" that:
-- "the Lord said" this or that horrible thing
-- "the Lord did" this or that horrible thing
-- "the Lord commanded" people to do this or that horrible thing
KEEP THIS KEY IN MIND. Their functional definition of "the Lord" in the OT often included BOTH the attributes of Yahweh and the attributes of Satan. "The Lord" could refer to God's saving virtue OR to Satan's killing wrath. They were wrongly joined at the conceptual hip. But Jesus came to forever separate and sever their connection.
Once we know the "personality" of Jesus, we will never again be able to assign the "functionality" of Satan to our heavenly Abba." When Jesus said He saw Satan falling from heaven, one aspect of that is that He saw all satanic qualities, which the Old Testament wrongly projected onto Abba's image, drop off and crash to the ground.