Evil, as the relative absence of good
Evil already shown as a power in scripture deployed by God no less, not a void created by lack of something else.
Darkness is just as real as light, and not caused by the lack of light as any casual glance into the night sky can show. Is night not real because the sun isn't up? I think we should turn out the lights on darkness and evil not being created by God.
However, conceptualizing the devil as God's equal and opposite is a fundamentally polytheistic or Manichaean idea
I've never made such a claim so we can move past that one as well.
That evil has no independent metaphysical existence doesn't negate its impact in the world
Evil is personified in the form of the adversary, the devil, Satan who wields that very power. An adversary who steals, deceives, invokes evil lawless thoughts in people, can speak from a person's mouth, act lawlessly, and eventually kills.
I'd suggest evil and the devil are quite intimately linked. Yet still subject to God as a lesser state and stature than God, as all of creation is in fact a lesser state or stature to some degree or another.
The same can be said with anything in creation. Even our imaginations, wrongs and ignorance serve His Purposes, somehow. Not sure how in many cases but it does.
Your attempt essentially tries to say evil has no existence however it is real and has real consequences. Saying it only exists because of a lack of good is like saying we exist because of a lack of God. IF God is good and Omnipresent there is no lack of good. Perhaps a sidebar.
We do not exist because of a lack or void of God.
This parasitic nature of evil is a key concept in understanding its dynamics. It doesn't create; it distorts and perverts what already exists. This helps explain why evil often appears so powerful: it leverages the energy and potential inherent in good, twisting it to destructive ends.
The idea of evil as a parasite also offers a framework for understanding how to combat it. Rather than confronting evil as an independent force, the focus should be on cultivating and strengthening good. By nurturing virtues, promoting justice, and fostering compassion, we create an environment less susceptible to the corrupting influence of evil. Just as a healthy body is better equipped to resist disease, a society grounded in strong moral principles is more resilient to the destructive effects of evil.
I think we've managed to say evil is quite real and we can agree on that.
The point will stand that God has in fact bound everyone to disobedience in order to demonstrate His Mercy in Christ. And IF that is the endgame then God is completely justified in doing so.
Just as hiding Himself causes Hope for Him to spring up in us, He again remains completely justified and uses that obfuscation to create HOPE.
There are many adverse situations in life that causes us to to have compassion and love. Mercy even. And in all these things God has His Hand ever in play.
I can not logically rule God out of anything in His creation. It doesn't make sense to do so, as that would be no God or a lesser God.
IF we're going to believe in God it may as well be A Divine Superior above all things, wouldn't you say?