You are asking me do i know of a Free Will? The question you should be asking is "If i have free will which knows good and bad, then "God who is perfect cannot be possibly perfect because he knows of free will which has a good and bad side to it"
So the best answer i can give you without anyone actually knowing the existence of free will correctly is there is no such thing as free will. Let me give you an example of what free will is:
Free = being able to do anything you want without limitations
Will = The willingness to be able to do anything you want without limitations.
Unfortunately this does not apply to "any" single being that can do every single thing without limitations. So in that respect Free Will does not exist.