Consider Isaiah 10- the Assyrian. The Assyrian king is called by God the “rod of Mine anger”, yet permissively from the position of God. If you step back to consider what God plans to do: His perfect will is to correct His people, bring them to repentance, and they follow Him. So knowing this, and that in the deepest way, He loves His own people- the apple of His eye, yet they have become sinful. He intends correction of Israel, with the intent of using the sinful Assyrians.
It is in the sinful heart of the reprobate Assyrian king to conquer nations. He has a stout heart and glories in his high looks- he is sinful already. God does not make the Assyrian sinful… because the king is already full of sin in the same way the Sabeans were in Job 1. God is left out of their lives, and they do what comes naturally snd easily to their sinful nature and mind. In Isaiah 10 verse 7, it is not the intention of the Assyrian to do the will of God. He contemplates the countries that have conquered other countries, and he desires to be like them. His sin is his desire. To be noted, those other countries were filled with idols that could not deliver them from being conquered. Israel was also filled with idols- and God is going to show Israel their idols cannot save them against the Assyrian.
Again- step back and ask- what is the perfect will of God here? Is it the destruction of Israel, or the desire for them to repent?
Does God destroy them directly, or does God permit the inflamed sin and evil- which already exists in the heart of the Assyrian – to accomplish His divine will? Does God step back, remove His presence, and let Assyria become more inflamed with sin? Does God step back from His protection of Israel, opening them up to the inflamed sinful passion of the Assyrian? When Israel is spoiled and trampled down, and their idols and possessions are taken, can they call on those idols of wood and stone to save them? Those dumb idols that cannot move or speak?
These actions of the Assyrian are done with God’s permission by the withdraw of His grace and protection from Israel. God used Assyria as a tool of judgment. This allowance of Israel’s destruction is a passive decree. The active decree in the text is the punishment of the Assyrian, and the wasting of the Assyrian’s people- God by active decree destroys them because they were evil and stout hearted.
Now- read this chapter several times. Do not turn to Calvin. Do not turn to Thomas Aquinas. Leave the Confessions. Pray to the Holy Spirit for wisdom. Sit for an hour and watch the text and be silent before God. Let the text speak of its own accord as it has for thousands of years. It can, and it will. The beauty is letting God teach you through the Holy Spirit to see the majesty of His workings.
Understand that God is good to His own – whom He actively protects – yet chastises. God also allows evil to exist by the withdraw of His goodness – letting them (the sinful Assyrians) do the inflamed sin that comes by their nature. God does not need an accelerant to make those sinners burst forth in their sin; all He has to do is withdraw His restraint, and they break forth in their own sin.
So it is with the sinner. The unregenerate sinner’s position becomes worse when God’s restraint is withdrawn until they are consumed with their sin.