I've always been of the strong conviction the God of reason never expected us to check our brains at the door, that there is such a thing as common sense, logical truth, that, for instance, regardless one's theology, 1 + 1 = 2, "if so, then...", etc. Since evil is not in God's will, demonic evil MUST be of somebody else's will:
James 1:13 Let no one say when he is tempted, "I am tempted by God"; for God cannot be tempted by evil, nor does He Himself tempt anyone.
God is not even tempted to do any evil. And can it be anything but Sunday School Christianity, to even a child, that God is perfect and has a perfect will, which involves no sin? You cannot, even as a causal agent, tie God to sin, without accusing the Creator of creating sin. The fall of Satan is in scripture, what happened clear, that the devil devised to become an upstart on his own, in his own heart:
Isaiah 14
12 " How you are fallen from heaven, O Lucifer, son of the morning! How you are cut down to the ground, You who weakened the nations!
13 For you have said in your heart: 'I will ascend into heaven, I will exalt my throne above the stars of God; I will also sit on the mount of the congregation On the farthest sides of the north;
14 I will ascend above the heights of the clouds, I will be like the Most High.'
15 Yet you shall be brought down to Sheol, To the lowest depths of the Pit."
There's hardly a picture of somebody who is more Godlessly, narcissisticly evil of will, everything I, I, I to the devil, me not Thee, in all scripture. Narcissistic, carnal man suffers this exact same disease.
God made the devil do nothing. Sin, of both man and demon, are our own red wagons. End of discussion.