The concept of omniscience in rooted in the idea of God’s “perfection”. In platonism, the perfect cannot change. Thus, if god changed (such as learning new information) then god would not be perfect. Omniscience, then, is an extension of platonistic musings on perfection. Christianity, early in its infancy, adopted these notions of perfection and with it an idea of Omniscience in which God’s knowledge does not change. This is why there is such great objection to Open Theists who want to redefine omniscience to mean knowing “all things current”. Redefining omniscience to allow God’s knowledge to change divorces Omniscience from its roots in platonistic perfection.

Modern Christians often say the following:

Even reason teaches us that no change is possible in God, since a change is either for better or for worse. But in God, as the absolute Perfection, improvement and deterioration are both equally impossible.

This is from the most popular systematic theology book today: Systematic Theology by Louis Berkhof. This reasoning is ubiquitous in Christianity, everywhere from gotquestions.org to “refutations” of Open Theism.

This line of reasoning comes straight from Plato, and is nowhere found in the pages of the Bible. To Plato, god was immutable because any change would be for the worse:

But surely God and the things of God are in every way perfect? Of course they are. Then he can hardly be compelled by external influence to take many shapes?… If he change at all he can only change for the worse, for we cannot suppose him to be deficient either in virtue or beauty… Then it is impossible that God should ever be willing to change; being, as is supposed, the fairest and best that is conceivable, every god remains absolutely and for ever in his own form.

But, plenty of perfect things change. A perfect baby changes. A perfect river changes. A perfect clock changes. But this is not quite what this maxim was designed to describe. Instead, this maxim was meant to describe Plato’s theory of forms, that the material and changeable is corrupt, and that somewhere in an eternal heaven is a perfect form of those things, never changing. The doctrine of perfection is a doctrine of platonistic dualism in which change (the material world) is corrupt and immutability (the heavenly realm) is perfection.

Plato writes:

First then, in my judgment, we must make a distinction and ask, What is that which always is and has no becoming; and what is that which is always becoming and never is? That which is apprehended by intelligence and reason is always in the same state; but that which is conceived by opinion with the help of sensation and without reason, is always in a process of becoming and perishing and never really is. Now everything that becomes or is created must of necessity be created by some cause, for without a cause nothing can be created. The work of the creator, whenever he looks to the unchangeable and fashions the form and nature of his work after an unchangeable pattern, must necessarily be made fair and perfect; but when he looks to the created only, and uses a created pattern, it is not fair or perfect.

In Plato’s mindset, “the perfect” was abstract and “the corrupt” was the material world. Change implied imperfection. Change is a feature of imperfection. But because god is perfect, god does not inhabit change. Instead, god falls within the changeless realm:

Now the nature of the ideal being [the Platonistic god] was everlasting, but to bestow this attribute in its fullness upon a creature was impossible. Wherefore he resolved to have a moving image of eternity, and when he set in order the heaven, he made this image eternal but moving according to number, while eternity itself rests in unity; and this image we call time. For there were no days and nights and months and years before the heaven was created, but when he constructed the heaven he created them also. They are all parts of time, and the past and future are created species of time, which we unconsciously but wrongly transfer to the eternal essence; for we say that he “was,” he “is,” he “will be,” but the truth is that “is” alone is properly attributed to him, and that “was” and “will be” only to be spoken of becoming in time, for they are motions, but that which is immovably the same cannot become older or younger by time, nor ever did or has become, or hereafter will be, older or younger, nor is subject at all to any of those states which affect moving and sensible things and of which generation is the cause. These are the forms of time, which imitates eternity and revolves according to a law of number. Moreover, when we say that what has become is become and what becomes is becoming, and that what will become is about to become and that the non-existent is non-existent-all these are inaccurate modes of expression.

In Platonism, this concept was very important. This is why god cannot become jealous, this is why god cannot have parts, and this is why god cannot learn something new. For God to learn something new, this implies change in god. But change is impossible.

Very early in Christianity, these Platonic concepts were adopted. God’s entire being was centered around this idea of changeless perfection. Philo of Alexandria, a platonistic Jew in the time of Jesus, says the following on God’s repentance in Genesis 6:

Perhaps some very wicked persons will suspect that the lawgiver is here speaking enigmatically, when he says that the Creator repented of having created man, when he beheld their wickedness; on which account he determined to destroy the whole race. But let those who adopt such opinions as these know, that they are making light of and extenuating the offences of these men of old time, by reason of their own excessive impiety; (22) for what can be a greater act of wickedness than to think that the unchangeable God can be changed? And this, too, while some persons think that even those who are really men do never hesitate in their opinions, for that those, who have studied philosophy in a sincere and pure spirit, have derived as the greatest good arising from their knowledge, the absence of any inclination to change with the changes of affairs, and the disposition, with all immovable firmness and sure stability, to labour at every thing that it becomes them to pursue.

Philo denounces, in strong terms, those who think that God can repent. The issue at stake is not God’s knowledge. This issue is not that God is learning something new. The issue is that repentance implies change. God foreknew the wickedness in man, not because God has “all knowledge”. But God foreknew the wickedness in man because any new information would be a change that would destroy the godhead.

Augustine, similarly states in his writings on the Trinity:

But other things that are called essences or substances admit of accidents, whereby a change, whether great or small, is produced in them. But there can be no accident of this kind in respect to God; and therefore He who is God is the only unchangeable substance or essence, to whom certainly being itself, whence comes the name of essence, most especially and most truly belongs. For that which is changed does not retain its own being; and that which can be changed, although it be not actually changed, is able not to be that which it had been; and hence that which not only is not changed, but also cannot at all be changed, alone falls most truly, without difficulty or hesitation, under the category of being.

Changes, even the slightest change, would destroy God. This is why God’s knowledge of the future is set. From Augustine’s writings on the Pelagians:

For the ordering of His future works in His foreknowledge, which cannot be deceived and changed, is absolute, and is nothing but, predestination.

The early Platonized Christians were obsessed with immutability. This was the core attribute of God. The quotes can be multiplied indefinitely. All else flowed from God’s unchangeableness, even God’s omniscience. Omniscience is not a Biblical concept. The concept of Omniscience is rooted in “perfect being” theology. Omniscience is a quality of immutability, and has little to do with God’s knowledge. For this reason, redefining Omniscience into a concept that does not involve immutability, is destined for failure.