My recent reply to a question on free will generated lots more questions and comments -- which usually happens when I tackle any of the great mysteries of God, life and freedom. Here is one example and my response:
QUESTION: Knowing and causation are two different things. I may know it's going to rain tomorrow; that doesn't mean I caused it. In Psalm 139:4, King David writes, 'Before a word is on my tongue you, Lord, know it completely,' and in verse 16, 'all the days ordained for me were written in your book before one of them came to be.' . . . This clearly indicates God does know what we'll do next. If God doesn't know what we'll do next, He is not truly sovereign, but rather reactionary to his creation. The prophets were chosen by God before they were born. They did not become prophets of their own will.
-- Excerpt from T., from Irvine, California
It comes down to this question: Are we truly the authors of our own lives? We must be if we are to be morally accountable for our actions. We must be if we are to choose freely to love one another and God, and we must be if we are to be truly set apart from all other living creatures who are moved by instinct, not by free moral choice.
The swallows don't choose to return to Capistrano. They're driven to return, coerced to return. They can't decide not to return. God created them to migrate, so God knows perfectly what they will do. However, God made us to choose between good and evil, between following and disobeying God, and because our choices are free and not predetermined, God cannot know what we will choose.
We are in nature, but not a part of nature, by virtue of this unique freedom of the will. Freedom is the essential prerequisite for moral responsibility. This is why we are not morally culpable for coerced actions, such as someone putting a gun to our head and making us obey.
An act that God knows we will choose is in this sense coerced because we can't make another choice. God does not cause our choice, but God cannot know our choices. We can predict the weather, and predict how our children will behave, but these are just predictions, not certain knowledge.
God may know that "the inclination of man's heart is evil from his youth." (Gen 8:21), but God cannot know if we will choose evil now. This is why God set before us a choice between blessing and curse, between life and death, so that we can choose life (Deuteronomy, 30:15-20).
This limitation of God's omniscience is why God "regretted making man" before the flood (Genesis, 6:6), and this is why God put the forbidden tree in the Garden, not because God knew what Adam and Eve would choose, but to see and learn from what they did choose (Genesis, 2:16-17).
The reason all this matters is that, according to the ancient Greeks, Fate (moira) rules our lives, and we have no control of our destiny, but the Bible is not a work of ancient Greek philosophy. The Bible is the great alternative to that and all determinisms like those developed by Marx and Freud, and in our time, sociobiologists. That's why religious determinism like Calvin's notion of predestination never gained wide religious acceptance.
The sad truth is that a part of us wants fate to rule our lives. A part of us wants to drift through life ignoring and evading our free-will choices. Freedom is funny that way. It's both the most desired and most feared human virtue and divine gift.
The slaves leaving Egypt wanted to leave for freedom's sake, but at times they also wanted to return to Egypt for security's sake.
It's time for us to see God's gift of free will not as a limitation, but as God's greatest gift to humanity. Free will frees us from being God's puppets and enables us to become God's partners.