Hard determinism will typically say we don't have free-will. Even in the position of hard determinism, free-will is accommodated in some schools of God believers. Not in a naturalistic philosophical manner, but within the theology where God has knowledge. The problem remains we tend to think God knows what I will do the next minute, and there is only one variable. Do you understand? One variable means I am going to drink tea at 5:15 PM today and that's the only think I am going to do at that time, and God knows it. I have no other option or any chance of doing anything else.
IN this case also, what you should know is that this knowledge of God matter could also mean God knows every single variable. Just that, we don't understand the variables. This is one school of thought.
Nevertheless, philosophers argue about determinism and libertarianism. Atheists too. A lot of atheistic philosophers argue for determinism, as well as the flip side. Thus, even some atheists dont believe in free will, and claim that we have already been determined in our actions. Thus, this is not necessarily a God problem.
So bottomline is, a strong position is that every occurrence, action, are either determined by causality, or random. What one must think about is that lets say a person is today worrying about free will, what caused him or her to do so? Was it nurture or nature? Lets say it was nurture, then maybe the society or the parents had some influence on them. If its nature, he was born to worry about free will. Thus, considering nurture again, what nurtured the parents or the society to influence him? Why did they question it, act in a certain way, or speak out? Did they also do it that way because it was all determined? Or is it a combination of nurture and nature both? Were they all determined to have this combination?
One would think if we have nurture and nature both in a particular event, can we have conflict in our minds prior to this event and the outcome of that conflict will decide what the event is or its outcome?
Compatibilists, which a school of thought say that this nature and nurture will give weight to both sides of the scale in our decision making process, and the heavier sides will tip the scale. So in this case prior to an event a human being will have multiple decisions to make, and that will have a causal chain which will also depend on decisions made with each link in that causal chain.
Now this is a purely naturalistic, philosophical argument for compatibilism.
Consider it carefully and apply that to your theistic model of God, free-will, and knowledge. Lets see where it could go.