Evangelical theologians have rarely proposed any significant revisions to the doctrine of God as understood to be taught in Scripture and handed down by Protestant thinkers.  There have been some differences concerning God’s eternity (with some seeing this as timelessness and others as everlastingness), and God’s love (interpreted differently by Calvinists and Arminians).  But, despite such occasional differences, evangelical scholars have in the past agreed that God’s omniscience includes infallible and exhaustive knowledge of the past, present and future. 

In 1986 Clark Pinnock argued from an Arminian perspective that even God does not know with absolute certainty what people will do with their ‘free will’, for, if he did, the will would not be truly free.  Pinnock pointed out that from Scripture that God appears to change his mind in response to prayer.

Pinnock portrayed God’s relationship with the world, especially with free humanity, as a dance: God leads, but human beings play their parts.  God’s will and ways are flexible, and God responds to human beings.  God is omniresourceful as well as omnipotent; while he can be surprised, he cannot be thwarted.

Then, in 1994, The Openness of God: A Biblical Challenge to the Traditional Understanding of God was published, with contributions from Pinnock, John Sanders and others.

The authors agreed with Pinnock’s earlier essay and defended it in light of church history (as corrupted by Greek philosophy), contemporary logical analysis (divine foreknowledge is incompatible with freedom and responsibility), ordinary Christian piety, and devotional practice (Christians pray as if prayer changes the mind of God), and systematic theology (divine foreknowledge is inconsistent with other beliefs such as the fall of Adam and Eve).

In 1998 John Sanders published The God Who Risks: A Theology of Providence, in which he argued from Scripture that God takes risks, and that risk raking is incompatible with absolute foreknowledge.  God’s whole project of voluntarily condescending to enter into time and history involved genuine risk.  He could predict the likely outcome, but not foreknow it with absolute certainty.  Sanders makes much of divine relationality, so that God’s immutabiity, for example, is understood as his faithfulness.  God’s knowledge of the past and present is absolute, but he knows the future only as a realm of possibilities.  God knows the future insofar as he decrees what will happen, but (says Sanders) he does not know every detail of the future exhaustively.

Another advocate of open theism is Gregory Boyd, who in his 1994 book Letters from a Skeptic argued that qualification of God’s foreknowledge helps to solve the difficult problem of evil.  According to Boyd, if God had foreknown the Holocaust with certainty, he could and would have prevented it.  Boyd also applied such thinking to spiritual warfare: if God already knows with certainty what will happen in the future, then spiritual warfare loses its meaning and urgency. 

Then in 2001 Pinnock published Most Moved Mover, in which he distanced himself from process theology.

Critics of open theism accuse it of diminishing God’s glory, and of contradicting his sovereignty.  Some, while not necessarily agreeing with the open theists, defend their right to question the received evangelical tradition.

Although the controversy has proved divisive it has at least forced evangelicals to reconsider the grounds of their beliefs about God.

Based on Olson, A-Z of Evangelical Theology, 325-328