Reformed Christian theology teaches that God, from all eternity, by the most wise and holy counsel of his own will, freely and unchangeably ordained everything that comes to pass (Ps. 33:11, Heb. 6:17, etc.; see also WCF 3.1). In other words, all things come to pass because God decreed them. He works out everything in conformity with the purpose of his will (Eph. 1:11 NIV). God predestined some unto salvation because it was his good pleasure, not because he foresaw some choosing Christ.
Not everyone agrees with this view. Some people say that it detracts from human freedom, so they speak of God’s middle knowledge. That is, although God knows all the possibilities of what might happen in the future, his decree depends on man’s choices and actions. In this view, God decreed that which he foresaw would happen. For a simple example, long ago God knew every possible action and choice Billy might make, but he only decreed that which he foresaw Billy actually doing. God’s decree comes after his foreknowledge of Billy’s actions. His decree is dependent upon Billy’s actions. This view is an attempt to harmonize freedom of the will and God’s omniscience and sovereignty.
Reformed theology strongly opposes this teaching of middle knowledge. Herman Bavinck critiqued this well as he explained middle knowledge:
[Middle knowledge teaches that] God does not derive his knowledge of the free actions of human beings from his own being, his own decrees, but from the will of creatures. God, accordingly, becomes dependent on the world, derives knowledge from the world that he did not have and could not obtain from himself, and hence, in his knowledge, ceases to be one, simple, and independent—that is, God.
Conversely, the creature in large part becomes independent vis-à-vis God. The creature did indeed at one time receive “being” (esse) and “being able” (posse) from God but now it has the “volition” (velle) completely in its own hand. The creature sovereignly makes it own decisions and either accomplishes something or does not accomplish something apart from any preceding divine decree. Something can therefore come into being quite apart from God’s will.
The creature is now creator, autonomous, sovereign; the entire history of the world is taken out of God’s controlling hands and placed into human hands. First, humans decide; then God responds with a plan that corresponds to that decision. …What are we to think, then, of a God who forever awaits all those decisions and keeps in readiness a store of all possible plans for all possibilities? What then remains of even a sketch of the world plan when left to humans to flesh out? And of what value is a government whose chief executive is the slave of his own subordinates?
In the theory of middle knowledge, that is precisely the case with God. God looks on, while humans decide. It is not God who makes distinctions among people, but people distinguish themselves. Grace is dispensed, according to merit; predestination depends on good works
Bavinck made it clear that Reformed theology firmly rejects middle knowledge because it strays from the teaching of Scripture that God – not man! – is completely omniscient and sovereign. He is on the throne, we are not. We are but clay in the hands of the Potter (Jer. 18:6, Rom. 9:21). Not to us, but to Him be the glory (Ps 115:1)!