For clarity, some words need to be defined
Omnipotence: having very great or unlimited authority or power.
Omniscience: having complete or unlimited knowledge, awareness, or understanding; perceiving all things.
Transcendent: Being above and wholly independent of the material universe having continuous existence outside the created world. Free from the limitations inherent in matter beyond all physical laws
Immanence: to be fully present in the physical world and thus accessible to creatures in various ways.
Is God learning or progressively knowing more about the universe, or does God actually completely exist out of time?
The view is that God is in time now since the beginning of the world, but that does not exclude His transcendence. God is in time so he knows what time it is as in the universes as a whole as well as what your clock says – say 12H45. His knowledge is constantly turning over as time goes on. It is not as though He is learning anything new in the sense that there are facts that he did not know before, In one minute it will be 12H46 and then one minute later 12H47. That is like learning something new but it is not as though it caught Him by surprise or he was ignorant. So God's knowledge is constantly changing in virtue of him being in time and knowing what time it is, he knows the exact state of the universe. So in that sense, because that is always changing, his knowledge will always be changing too.
How does that affect the doctrine of salvation, or how God actually knows us and has called us to be his children, and whether we are actually able to make a decision. The claim is that God's foreknowledge of future free acts is incompatible with human freedom The argument there is that if God knows that you will do X, then you must do X – it is fated and you necessary will do X. That is a logically fallacious argument. From the fact that God foreknows that you will do X, it only follows that you will do X, but not that you must do X. You could refrain from X, but if you were to refrain, then God would have foreknown that. So there is no incompatibility between God's foreknowledge and our freedom. In particular his foreknowledge of those who will place their faith in Christ and be part of the elect.
If we do understand God's characteristics it is very important is that God is omniscient (knowing everything). Traditionally a person is omniscient if for any proposition that person knows that proposition and does not believe the opposite of that proposition. An omniscient person would be
someone who knows only and all truths. What kinds of truth- there are truths that exist and truths that do not exist. The possible truth (best defined in terms of propositions), a proposition is the information content of a declarative sentence. Any declarative sentence expresses a certain information content and the idea of omniscience is that there is no fact of the matter, there is no true information that this person does not know. And he believes no false proposition, so he would know only all facts. But there are more things in the world than just pure facts. There is another type of knowledge that we could call non-propositional knowledge. This would be knowledge for example how to ride a bicycle or how a watermelon tastes or things of that sort. But omniscience is not typically defined for example how it feels to be a sinner, and clearly God could not have that kind. Therefore omniscience is defined in terms of propositional knowledge of knowing only in all truths but not necessarily having all non-propositional knowledge.
The Jesuit theologian Luis Molina said is that although everything God knows he knows at once. Nevertheless there is a kind of priority in God's knowledge, a sort of logical order or an explanatory order and he said at the most fundamental level is natural knowledge, and this would be God's knowledge of everything that is necessarily true (eg 2+2=4, everything that has a shape has a size)
This knowledge is natural to God and essential to God. Molina called it natural knowledge, and this would include God's knowledge of all possibilities - everything that could happen in every possible world – that is logically possible. To jump to the third area or tier of His knowledge - free knowledge. This would be God's knowledge of all true contingently, true propositions that are dependent upon his
will. These are contingent truths because God chose a certain world to actualize. In the middle, the second tier is what Molina called middle knowledge. This is God's knowledge of what every possible person that he could create would freely do in any circumstances God might place him. So God would know for example that Peter in a certain set of circumstances would deny Christ three times
There are quite a few people who doubt that God has middle knowledge. But if God is omniscient it seems like it would be a necessary component of omniscience.
Middle Knowledge holds is that God not only knows everything that could happen, all the possibilities, but He knows everything that would happen under other circumstances. So this is a very different kind of knowledge than foreknowledge. This is not knowledge of the future. The things that God knows by
a middle knowledge may never come to pass.
To use terminology of ‘subjunctive conditionals’ statements, these are an ‘if-then’ statement in the subjunctive mood. We are not very familiar with these. The subjunctive mood is a mood that is used to express contrary to fact situations, like if I were rich I would buy a Mercedes. I am not rich and I
have not bought and will not buy a Mercedes. Indicative conditionals are conditionals in the ordinary indicative mood. A good example to illustrate the contrast this: if Oswald didn't shoot Kennedy somebody else did. Every one of us would agree with the truth of that indicative conditional because we all know Kennedy was assassinated. If Oswald did not shoot him somebody did. So that indicative conditional is clearly true. But now consider the subjunctive conditional: if Oswald hadn't shot Kennedy somebody else would have. Is that true? Well that is not at all obviously true unless you are a conspiracy theorist and you think there was another gunman on the grassy knoll.
There is a huge difference between these subjective conditionals and indicative conditionals and the
theory of middle knowledge is that God knows the truth of all of these subjunctive conditionals. If you
had been the Roman prefect of first century Palestine you would have sent Jesus to the cross, you would have done what Pilate did. Or if you had been in ancient Israel you would have been a Jewish monotheist. Those are the sorts of things that God is said to know by means of his middle knowledge.
An Old Testament example is when David flees from King Saul. David goes down to a town a city
Keilah. David asks the priests (who have divining stones called an ephod) if he remains in Keila would
Saul attack the city. The ephod says ‘yes’. So David asks a second question: if Saul comes down to
attack will the men of Keilah turn him over to Saul, and the ephod said ‘yes’ . Whereupon David flees the city - so that Saul does not come down and the men of Keilah do not turn him over.
The ephod was not giving him for knowledge of the future - it wasn't telling him what will happen because we know those things didn't happen. Saul didn't attack the city, the men of Keilah did not turn him over. Rather this knowledge was subjunctive conditionals: if David were to remain in Keilah Saul would attack the city; if Saul were to attack the city the men of Keilah would turn David over to Saul. This is one of the proof texts that is used to show that God in fact does have middle knowledge.