Open theism in 850 words! Quite a challenge! Especially for a complex and shifting philosophical view of the relationship of divine sovereignty to human freedom, said by many to be the most heated debate within evangelicalism since the debate over inerrancy in the 1970s.

Known variously as 'Open Theism', 'Free-Will Theism', and 'The Openness of God View' and 'Open-View Theism', the issue – divine foreknowledge – has been a topic of theological debate since at least the time of Augustine (who wrote a famous treatise on the subject Freedom of the Will). What and how God knows events that (to us) are still future raises more than one issue. To begin with, it clearly affects how we understand God in himself – is he really sovereign? If we should draw the conclusion (as open theists do) that there are aspects of the future that God does not know then clearly God's sovereignty is limited in some way; there are things over which he does not have ultimate control. Additionally, at issue is the nature of human freedom and the meaningfulness of prayer. How 'free' are we in making choices or asking for things to change? Is it merely an apparent freedom but not a genuine one? If God orders all things (plans and brings to pass) does not this imply that human freedom is a smokescreen that covers what in effect is a view that makes us automatons.

Open theism asserts that God knows the future only as a set of possibilities­ what would happen within a set of parameters. God knows how free agents would act within any possible world, a view sometimes referred to as middle-knowledge (first asserted with philosophical passion by a sixteenth century Spanish Jesuit priest named Luis de Molina).

Its contemporary advocates – Greg Boyd, John Sanders, William Hasker, Richard Rice and Clark Pinnock are five of its ardent exponents – argue that God does not exercise control of the universe in any absolute sense but leaves it open allowing for truly 'free' human decisions to take place. The argument of the relationship of determinism to freedom is of special interest to Calvinists in its disagreement with Arminianism, especially on the nature of predestination and foreknowledge (though to be fair, the issue is more nuanced that the sixteenth century debate and classical Arminianism never affirmed some of the things currently asserted by open-theists). To allow for real choices, God cannot therefore determine the future (as in election and providence) and therefore is not omniscient in any meaningful definition of the term. Calvinists have always suspected that Arminians (consistent ones at least) in their attempt to salvage true freedom have in the process paid a high price – the loss of God's control of the future and therefore the loss of any possibility of assurance of lasting salvation, a sustaining providence in difficult times, and (ultimately) any guarantee that good will triumph over evil. The advocacy of what has been called "a risky future" in the interests of sustaining absolute human freedom is, well, risky! There can be no ultimate guarantee of a certain future.

Of course, Open Theists do cite Scripture. Among the passages they appeal to are: passages such as Genesis 6:5-6 where God regrets that he has made man; or, passages where an outcome looks surprising even to God as in the words of Jeremiah 3:6-7 where God sounds surprised by the fact that Israel has turned to worship idols; or, passages where God tests people because he needs to know their character as in Abraham's offering of Isaac in Genesis 22. Greg Boyd even cites Romans 9 (citing Jeremiah 18). When Paul says that God is the potter and we are the clay, he doesn't mean (as the passage suggests!) that God is determining the shape of how things will be. He means that God is very flexible. He is a flexible potter. If we choose one thing, he will make us one way, and if we choose another way, he will make us another way.

Traditional responses to these passages, from John Calvin onwards, is to insist that God only speaks this way because we are too frail and finite to understand the ways of God. For example, God does not really repent; he only appears to do so because he speaks to us as though we were children. And if we baulk at the appearances of divine sovereignty and say, "But that's not fair!" then the Bible has already stated the question for us. And it has also answered it: "But who are you, O man, to answer back to God? Will what is molded say to its molder, 'Why have you made me like this?' Has the potter no right over the clay, to make out of the same lump one vessel for honored use and another for dishonorable use?" (Rom 9:20-21).

Perhaps the Psalmist put his finger on the real problem of open theology when, in another context, he penned God's accusation upon a wayward people by saying, "you thought that I was one like yourself" (Psalm 50:21).