A few years ago, I became familiar with part of the Puritan Jonathan Edward's writings on the subject and it has shaped my own understanding significantly. Summarizing, here's how I think the whole divine sovereignty/human freedom argument is best resolved:
Man's choices are freely made, but with a few caveats:
- Man's freedom is not "final." That is, the universe is not a closed system. God can (and does!) intervene in it and can overrule both man's choices and the consequences of those choices. For example, if I jump out of a plane and my chute doesn't open, God can either save my life or let me die. As sovereign God, He can also ensure that my car doesn't start so I never make it to the airport, and thus, never jump. Thus, my choice was freely made, but it is not final in the sense that God can (and may) overrule both it and any consequences flowing from it.
- Man's freedom is not "sovereign." A man does not have the ability to do anything that is possible. Both his character and his circumstances put limits on his choices.
- Therefore, man's freedom is analogous (though finite!) to God's omnipotence. When we say God is omnipotent, we do not mean that God can do anything He wants to. What we mean is that God can do anything which He desires that is both possible and consistent with His nature/character as God. So, God cannot commit evil, cease existing, or do that which is a logical contradiction (such as create a rock too big for Him to lift). In a similar way, humans are capable of doing all things which are possible for humans (e.g., we can't walk through walls or levitate) and which are consistent with our nature.
- The Point: Redeemed humans can choose obedience or disobedience to God; unbelievers can't. Redeemed humans have both an old nature and the indwelling Spirit of God. Thus, they can follow the flesh and it's lusts or keep in the step with the Spirit. But an unbeliever's choices are limited by his nature/character. Since all they possess is an "old man," they freely choose to do that which it desires: evil and sin and rebellion against God.