Well, you are probably not going to like this, but I do indeed believe that God is neither fully omnipotent nor fully omniscient. So I can then claim that man can have free will without creating a contradiction. No doubt, you believe that the omniscience and omnipotence of God is Biblical; I disagree and politely suggest it is an idea that leaks in from the "caricature" of the Christian God that floats around in the air of our culture and which many take onboard as if by osmosis.
We agree on one thing, at least: If man has any freewill, this takes away from the "sovereignty" of God.
Hi expos4ever, have you ever seen the movie,
Mouse Hunt? If you want to see what could happen to the universe if even a single "
maverick molecule" existed in it outside of God's purview, watch that movie
As I believe has already been mentioned above, whatever is outside the scope of God's control, is God to Him. If a maverick molecule existed in the universe (or beyond it), God would still be a "ruler", and a powerful one at that, but He would not be "God". His word to us would be little more than conjecture and hopefulness, His prophesies and His promises to us worth little more than the paper they are written on (because He would have no way of knowing/guaranteeing that they would or could ever come to pass).
The Westminster Confession tells us that, "
God from all eternity, did, by the most wise and holy counsel of His own will, freely, and unchangeably ordain whatsoever comes to pass". IOW, whatever happens in this world, God knew it would happen beforehand (i.e. Psalms 139:1-16). Long before, in fact (Ephesians 1:4-6).
This does not mean that God "
causes" everything that happens (we certainly choose to sin without any help from Him, for instance). Many things, like sin, He "
allows" to happen (or we would not have free will).
Free will means that we normally have the ability to choose to do what we desire most at any given moment. This doesn't mean I am autonomous. For instance, I would never choose to pay taxes if I didn't feel I had to, but I do so because my "desire" to
NOT have the IRS put a lien on my home is greater than my "desire" to not pay my taxes

(well, there is that pesky command to obey the governing authorities .. i.e. Romans 13:1-7 .. and the fact that the even the Lord paid taxes, which might have something to do with it as well

).
There is much more to this, of course, but what it basically means it that
God is sovereign over all (omniscient, omnipresent, omnipotent, immutable....)
and we are free (but only within His purview and ordination, PTL).
Your and His,
David