It is one thing to say that God ordains evil’s existence. It is a very different thing to affirm that evil will not keep God from accomplishing His will for humanity and his creation.
God doesn’t create evil. He permits evil. He is not threatened by evil. He “uses” evil as He accomplishes His ordained good. God won’t always keep evil from happening. But, the evil that happens can be manipulated by God to be part of a process that will accomplish what God wants done. While the evil that happens has its “own” end in mind, God can make that evil fit into His ends. To say it differently, God can produce what for Satan are “unintended consequences”, consequences that are contrary to what Satan wanted the evil to accomplish.
The fact is that no one successfully orders God to do anything. No one can force Him to do anything. No one or nothing, such as evil, can put God in a box.
God can allow evil to produce consequences that match what God wants to happen to the unrepentant sinner, or that match what morality demands. God can forgive evil, without eliminating the results of evil.
If God prevented evil volition from producing “evil” results, allowing only “good” results to come from evil volition, what would happen? Morality itself would be destroyed. Moral decisions that produce no corresponding consequences eliminate the moral character that currently indwells His created universe.
When the moral character is eliminated, we need to invent a new word for what, up to now, we have called “human.” Maybe something like, “amoral carnivorous biped”, or “walking rock”, or maybe, “Ichabod” (the glory has departed).