Donald Sensing has written a good amount (including his MS thesis) on the subject of human free will, but I have another question: does God have free will?
On one hand, if God is all-powerful and reigns supreme over the entire universe, then it seems logical to conclude that he has free will. But on another, subtly compelling hand, can God lie? Could Jesus have sinned while he was on earth, and simply chose not to? Or, because of his divine nature, would it have been impossible for Jesus to murder, rape, steal, or disbelieve? If God is perfect, then in any given circumstance he must perform the perfect action. Can multiple actions be equally perfect? Considering that God knows the ultimate result of any action he may take, it doesn't seem likely that any two alternate decisions would end up with the exact same level of holiness.
Perhaps it would be impossible for God to lie, by definition. Whatever God says is True; anything that disagrees with God is False. Any decision God makes is Perfect, by virtue of the fact that he made it. That sort of reasoning (legitimate as it may be) does not easily extend to Jesus in the flesh. Living as a mere man, Jesus voluntarily decided to restrict his power and his actions, even though he had the authority to take whatever he wanted and to kill whomever he pleased. Looking at Jesus doesn't necessarily give us a true picture of God's behavior. Absent these assumed restraints, could Jesus have succumbed to Satan's temptations?
It would be hard to believe that I have a more free will than God himself has. If mankind was created in God's image, then we must share his essential attributes, and he ours.