In both Calvinism and Extensivism, God knows all that could happen, and all that will happen. The difference is in how he knows. According to Calvinism, his knowledge of what could and will happen is based upon his micro-determination. Another way of saying God knows what could happen is God knows what he could determine to happen. Similarly, another way of saying God knows what will happen is God knows, out of the possibilities of what he could determine to happen, what he will determine to happen. This determinism is not merely God determining to create the universe because we all believe that if God did not determine to create, creation would not exist.
Rather, in Calvinism, it is that God knowing what will happen entails that everything, thought, action, and event happens only because God micro-predetermined it to be precisely as it is. His micro-determinism is accomplished by and revealed in his decrees, foreordination, and endowment of man with compatible moral freedom. In this micro-determined universe, humans do not and cannot make a free choice in which the person could have chosen differently and is the efficient cause. That is to say, in the moral moment of decision, humans freely choose what they were predetermined to choose, but they cannot choose differently given their same past.
Extensivism argues God knows all that could and will happen because he is essentially omniscient. Therefore, God can know what he determined to happen apart from the influence of libertarian free human beings and what comes into being because of the actions and choices of libertarian free beings; these are known as contingencies. The only thing required is that God sovereignly chose to create beings with libertarian free choice. Below are seven components of what it means to be essentially omniscient.
- He knows everything.
- He eternally knows everything (Ps 149: 1-4; Prov 15:3; John 21:15-17). This knowledge includes even the seemingly most insignificant of realities like the number of hairs on the head of each person who has ever lived (Matt 10:30). The reason that God knows this ever-changing reality of billions of people is not because he causes it or is necessarily going to do anything with the knowledge, but rather because he knows everything.
- Foreknowledge is a word that accommodates humans since God has always known everything because he is essentially omniscient.
- He always knew every actuality, potentiality, and what potentials he would transform into actualities. Accordingly, when we speak of God’s eternal knowledge, it includes what we call foreknowledge.
- He is essentially omniscient.
- His omniscience is an essential property of his deity, which is also true of his omnipotence, omnipresence, omnibenevolence, and all other attributes and aspects of deity; therefore, he knows everything and cannot lack knowledge of anything.
- Essential omniscience entails at least the following.
- Nothing ever occurs to God; it cannot since there is nothing outside of his eternal knowledge that needs to become a part of his knowledge for him to know it.
- God does not learn perceptively, perceive knowledge. That is, he does not look outside of himself to learn or know about anything. For example, Calvinists often portray the Extensivist’s perspective as if God looks down the halls of human history or something akin to looking into a crystal ball to acquire knowledge of what humans do or will do; this is a caricature with no basis.
- God cannot hold a false belief because he is essentially omniscient and the sum of perfection. For example, if he knows something will happen, it will happen, and he cannot be wrong.
- While nothing ever occurs to God, and he always knows everything at the same time, he can distinguish between the sequences of events.
- Essential omniscience is based upon who God is and not on what he does. He Knew everything before he willed anything to be. To wit, His knowledge of the future is not based upon him having micro-determined everything, but, rather, it is based on him being the essentially omniscient God.
- He knows the libertarian freewill acts of humans.
- Freewill acts of humans are called contingencies.
- He knows them because he exhaustively and accurately always knew he would create humans and what constitutes being human; therefore, he knows everything about them and what they can and will freely choose to do.
- As the only eternally and essentially omniscient being, he cannot become informed or be informed by anything or anyone except himself.
- As an essentially omniscient being, he cannot have incomplete knowledge of humans; because he is essentially omniscient, that knowledge does not require determinism as its source other than his determination to create libertarian free beings. To suggest a separation between God’s exhaustive knowledge of what he created as a human being, and what humans would freely choose to do given an opportunity is a fallacy of artificially separating the after-effect of God’s creation from what he created. For such to be true would require the unbiblical proposition that God is not essentially omniscient because he lacks exhaustive knowledge of himself and his creation.
- Freewill acts of humans are called contingencies.
- His knowledge is not necessarily causal.
- It is a confusion of categories to conflate knowing (Epistemology) with causing (Etiology). Although my knowledge is not perfect, infallible, or exhaustive, which means I can be wrong, it is sufficient to illustrate causation is not intrinsic to knowing. For forty-four years, I have always known who Gina, my wife, would vote for when she goes into the voting booth. Thus far, I have never been wrong. However, that is not dependent upon me somehow causing her to vote for a certain candidate, but only because I know her well. The point of the example is not to demonstrate that I could not be wrong as is true with God but merely to demonstrate knowing does not equal causation, nor is it entailed in knowledge. To wit, determinism is one way of knowing, but it is not the only way of knowing. Therefore, to use my fallibility to nullify the example is unwarranted.
- God’s foreknowledge in Calvinism is causative since Calvinism generally contends that God can only know what he determines, and, therefore, denies that God can know contingencies the acts of libertarian free beings. In contrast, God’s essential omniscience entails that he knows those events that are determined (uninfluenced by human choice) and non-determined events (influenced by or the result of human choice), which are known as contingencies.
- He knows himself exhaustively.
- No aspect of his being, knowledge, or the composite of all of his attributes lacks perfect exhaustive eternal knowledge.
- He knows his intentions.
- God has always known himself, which always includes exhaustively knowing his intentions.
- He always knew he intended to create humans in his image with otherwise choice (libertarian moral freedom).
- God’s knowledge not only includes the significant counterfactual potentialities, it even includes the mundane such as knowing every sparrow that falls from the sky and the number of hairs on everyone’s head (Matt 10:29-30). Both states are ever-changing and rather unimportant, yet God has eternally known everything about each of them because he is essentially omniscient; such neither entails nor even suggests he micro-causally predetermined each changing state. To separate God knowing himself exhaustively, including his intentions, which includes his intention to create libertarian free beings from knowing the acts of such beings is baseless and artificial.
- Therefore, he eternally and innately knew what humans would choose because he exhaustively and eternally knew himself and his intentions, and he knew this without having to determinatively cause all human actions.
 I use Extensivism in its general sense as a synonym for non-Calvinism.
 I am referring to mainstream consistent Decretal Calvinism, or what I often term as Major-Calvinism. Major-Calvinists believe in at least unconditional election, irresistible grace, compatibilism, and that God predetermined the eternal destiny of everyone.
 Compatibilism is the belief that moral responsibility and determinism are compatible. Man is considered to make a free choice so long as he chooses according to his greatest desire. But it must be understood that while such choice is considered free, the desire from which it comes was determined by the individual’s nature and past. While God employs secondary causes in his determination, they are as determined as every other determinative antecedent that results in the determined desire from which the determined free choice emanates; therefore, when we speak of God determining to create in Calvinism, it entails every aspect of creation, thereby absolutely disallowing humans to make a libertarian free otherwise choice, to choose differently than the person did, in fact, choose in the moral moment of decision.
 Efficient cause means that we need look no further than the efficient cause to explain the cause of the event.
 Some Calvinists, as well as other determinists, contend that God cannot know the acts of libertarian free beings, contingencies.
 Libertarians contend determinism is not compatible with moral responsibility. Man possesses actual otherwise choice and can, therefore, act or refrain in the moral moment of decision, given the same past within a given range of options. In Christianity, God determines the range of options. Adam’s range of options prior to the fall was greater than mankind’s options after the fall. The range of options present prior to the fall was the result of creative grace.
Fallen man can still choose between options, but the range of options is less than man had prior to the fall. This lessening includes losing the ability to make choices that are inherently righteous or spiritually restorative (making one right with God) based solely on creative grace. In order to make an inherently righteous choice or one that is spiritually restorative, God had to provision redemptive grace, grace enablements.
Libertarian freedom allows for both determined events (events uninfluenced by human choice) and undetermined events (events influenced or caused by human choice) in which people choose between options. And whatever they did choose, they could have chosen differently.
 See Does God Love All or Some; Comparing Biblical Extensivism and Calvinism’s Exclusivism for a more comprehensive comparison between the two perspectives.
 He does know some things because he determined them to exist apart from human choice, but micro-determining everything is not essential to his knowing everything as it is in Calvinism.
 Many Calvinists attempt to superimpose Calvinism’s determinism upon what it means for God to be essentially omniscient rather than understand the term as used by Extensivism. The attempt, although impossible, is a form of “the same problem argument” wherein Calvinists seek to palliate the harshness of the entailments of Calvinism and compatibilism by suggesting that Extensivists have the same problem as Calvinists. When, actually, while each view may have problems that need to be addressed, we do not, and cannot, have the same problem given compatibilism and libertarianism since they are intrinsically opposites, and therefore, mutually exclusive.