free will
The reason evil is possible, the reason we can turn our hearts away from God, is that we have free will. I find that I can turn my will any way I choose. I can know what is right and do the opposite; I can have a strong desire and yet refuse to act on it; I can even choose to act in a self-destructive way. My will is free.
Yet my ability to will anything I choose does not mean that I can do anything I choose. I am often restrained from actually carrying out what I intend to do. One thing that often limits my action is physical reality: the laws of nature, my limited physical abilities, the resources available to me. I can intend to push my hand through a brick wall but I am not able to actually do so. Another way I am limited is the actions of other people, either because I need their help or because they intentionally try to stop my action. I can intend to rob a bank, but to actually do it I’ll have to also succeed in convincing some people to work with me and I’ll have to struggle against the many people who will try to prevent me from robbing the bank. So I find that while my will is free, I am not free to do everything. What actually happens is limited in many ways.
As human beings, we are in control what we want to happen, what we intend to happen. But we are not in control of what actually happens. What actually happens is influenced and limited by many things, too many for any one person or any group of people to understand and control. Only God can control what actually happens.
And I believe God does. But this doesn’t restrict the freedom of human beings to will whatever they choose. Our will is free, even when we cannot complete what we intend. Being limited or hindered by other people or by physical reality doesn’t prevent us from willing anything and hoping to find a way to do it, and even if what we will is completely impossible we can still stubbornly choose to will it. We can refuse to accept our limitations. We can rebel in our hearts against the way things are, even if there is no hope of achieving what we desire. We always have that freedom.