A standard Calvinist criticism about God’s prophecy as it relates to Open Theism is that there are too many free will agents for God to be able to accurately predict the future. This criticism fails on multiple levels. The first level is that prophecy often is subverted and sometimes fails (Calvinists resort to extreme mental gymnastics to avoid this clear fact). The second criticism is that human beings are able to accurately predict human action in spite of unknowns in human actions.
This concept is illustrated in I am Strange Loop:
When we turn our car’s steering wheel, we know for sure where our car will go; we don’t worry that a band of recalcitrant little molecules might mutiny and sabotage our turn. When we turn a burner to “high” under a saucepan filled with water, we know that the water will boil within a few minutes. We can’t predict the pattern of bubbles inside the boiling water, but we really don’t give a hoot about that. When we take a soup can down from the shelf in the grocery store and place it in our cart, we know for sure that it will not turn into a bag of potato chips, will not burn our hand, will not be so heavy that we cannot lift it, will not slip through the grill of the cart, will sit still if placed vertically, and so forth. To be sure, if we lay the soup can down horizontally and start wheeling the cart around the store, the can will roll around in the cart in ways that are not predictable to us, though they lie completely within the bounds of our expectations and have little interest or import to us, aside from being mildly annoying.
A few highlights. Events are predictable often in spite of individual elements (elements that we don’t even have to “give a hoot” about). Reality limits possible outcomes of events. We can use our actions to create better predictability. Unpredictable events are still often predictable within limits.
Human beings, although God watches us to learn what we will do (such as when God called the animals to Adam “to see” what he would call them), operate in similar predictable patterns. There are exceptions (and the Bible points these out when God exclaims “it never entered My mind that you would do this”), but the rule stands.
This rule that people behave in patterns is the foundation of economics (people respond to incentives). If the minimum wage is increased above the natural market rate, less people will be employable than before (and not at the same work load and benefits). If Venezuela tries to limit the price of toilet paper to less than the market price, country shortages will occur. If the government mandates that daycare providers must have licenses, then the cost of daycare will increase.
These are true independent of specific individual actions. In response to a minimum wage increase, an individual employer might hire more people. But they are the equivalent of a stray bubble. Their action has no ability to affect the whole. The aggregate is very predictable, in spite of the unpredictability of individual agents.
The predictability of events is highly dependent on how likely external and unpredicted events are likely to affect the outcome. Maybe an invention increases the productivity of low wage workers by ten times. In this case, raising the minimum wage would be accompanied by a massive increase in hiring. It would not be the minimum wage increasing hiring, but the invention. Economists could only predict the hiring increase if they knew about the invention.
When economists predict behaviors, they do not have the information to which God has access. One would naturally expect that God could predict events with much greater accuracy than humans. Adding in the fact that in most of God’s predictions, God is predicting the consequences of His own actions (God is not a fortune teller, but a military general). God is using his power and ingenuity to bring about His predictions. This is actually the point of Romans 8-11 (what Calvinists see as their key prooftext:
Rom 9:6 But it is not that the word of God has taken no effect. For they are not all Israel who are of Israel,
God had a plan. Israel thwarted God’s plan. God engineered a way to salvage His plan. God can keep his promise to Abraham while cutting off Israel for their unpredicted rejection of Him. That is Paul’s point. Even the collective actions of the primary occupants of God’s promise were not enough to thwart God’s agenda. The implicit message of Romans 8-11 is that God did not predict Israel’s rejection but has found a way to use and overcome that rejection. Romans 8-11 is precisely the type of prediction ability that one would expect in the God of the Bible (in contrast to the classical concept of God). These verses are highly Open Theistic.
In short, when Calvinists criticize Open Theism for prophecy, they need to understand in what ways and limitations things are reasonably predictable. They need to at least grant God prediction capabilities available to man, and distinguish how their points are substantially unique from these. And they also need to deal with how the Bible treats God and prophecy.