Don’t be silly.
Satan is the god (small g) of this world, but he can do nothing outside the power of the Lord. Recall Job and the interactions between the Lord and Satan?
If God doesn’t control everything - then He can’t faithfully and reliably execute any of His plans.
Satan can do what people let him do.
So by your logic....that little 9 yr. old girl died because God wanted to teach someone a lesson?
So...my SIL..was killed in a car wreck a couple months ago. God caused that to teach her husband and 4 kids a lesson? Or someone else a lesson?
Don't be ignorant....Read the NT.