Reading through Origen's On First Principles, I discovered that he used free will as a way of justifying God, to the point where he quite apparently says that all souls are born into different stations in life because of the good or bad they did in previous lives. Aside from the fact that this sounds more like a Hindu doctrine than a Christian one, I was struck by how much it differs from the Augustinian interpretation of grace. Calvin took Augustine to the extreme. For Calvin, there is no reason to justify God in the first place. God foreordains everything according to His good purpose, and if it makes no sense to us, it is only because we are so limited and/or corrupted.
Now being acquainted with these two extremes in Christian thought, I'm tempted to go the moderate route. It seems perfectly reasonable that God would create the world with creatures of various stations, not because of any question of merit, but rather simply because diversity is a good and beautiful thing (contra Origen). On the other hand, it also seems reasonable to think that many of these creatures have free will, and will be judged on the basis of what they do with their limited capacities, in proportion to the extent of those capacities. To suggest, as Calvin seems to do, that we can't use our common sense to understand what is right and wrong for God to do puts us in a pretty bad position when it comes to theology--how do we know that God is not actually a demon?
But the moderate route isn't entirely satisfying. If God isn't truly in control of everything that happens, how can we call Him Lord of all creation? There are many passages of Scripture that seem to attribute to God absolute power over human actions, even the human mind. So Isaiah 63:17--"Why, O Lord, do you make us stray from your ways and harden our heart, so that we do not fear you?" Or Proverbs 16:9--"The human mind plans the way, but the Lord directs the steps." Or Jeremiah 31:33--"I will put my law within them, and I will write it on their hearts." There are plenty of other verses which affirm human responsibility, but these are hard to ignore.
The difficulty in trying to justify God is trying to determine just what kind of universe He should have made. I suppose Calvin saw this more than most of us. It seems impossible to imagine a universe for which God could not receive some reproach. The fact that anything exists at all is a miracle and, at the same time, a condemnation--if I exist, I am doomed to be whatever it is I am and not something else. One could imagine that this horrible tension is the root of all sin. Adam and Eve had a paradise to live in, yet they still found themselves tempted by what it was not.
At the same time, to jettison all sense of justice by which to evaluate God's action is to destroy prayer as it is found in the Bible. There are, of course, the psalms, which make very direct complaints to God, calling on Him to remember His steadfast love and His promises. But the paragons of prayer are Abraham and Moses. Abraham negotiated with God over the destruction of Sodom: "Shall not the Judge of all the earth do what is just?" And Moses interceded for his people on the basis of reason: "Why should the Egytians say, 'It was with evil intent that he brought them out to kill them in the mountains, and to consume them from the face of the earth'?" If these men had been willing merely to accept God's plans, convincing themselves by some theological argument that whatever God did was right, they would never have been heroes of the faith.
I don't see any way out of the tension between what is and what is not. It seems to me the essence of life itself. We desire to reach a point of perfection, where we can finally stop and say, "It is enough." Yet we know that if we stopped completely, that would be an end to life itself. All life is motion and change. A perfect, finished worked of art is lifeless. It is only in the contemplation of that art, in the active appreciation, that we derive any pleasure from it.
Behold the central paradox of Christian theology. Christ did not consider equality with God as something to be grasped, but emptied himself, taking the form of a human being, and become obedient even to the point of death on a cross. He who knew no sin became sin. God took on imperfection in order to attain perfection.
What does this have to do with free will? Only that in Christian thought, free will relates to theodicy, the justification of God. Some will justify God's wrath by reminding us of our responsibility. Others will justify it by asserting God's supremacy. The argument goes back and forth eternally. The disagreement is honest. It is a living response; any resolution to the argument would mean we are no more than a lifeless work of art.
Prayer, more than debate, is a living response. Abraham and Moses argued their case before God. Jesus, and then Stephen the martyr, prayed, "Father, forgive them, for they know not what they do." Ultimately, the resolution of God's wrath is on the cross. Christ died for us while we were still sinners. We are told he even went and proclaimed the good news to the dead (1 Peter 3:19). For the Christian, then, there is limitless hope for the salvation of the world, of every soul. There is no reason to resign ourselves to believing in the eternal damnation of some for the sake of God's eternal purpose (contra Augustine and Calvin). God's eternal purpose is the cross, that impossible event which changes everything.
Jesus told his disciples to take up their own cross. This is the ultimate living response. Instead of justifying God by our theories, we ought to vindicate Him by imitating Him. Whether or not this is a free choice, I still don't know, but it is a choice: to take up our cross daily, to embrace the contradiction in our own lives between our desire to be and our desire to be something else.