  This is a broader topic than can be tackled here; instead, let us examine a few examples involving God's knowledge. If perfect in knowledge, God is all-knowing. If God learns something new, then before learning it, he was not all-knowing.  Even if the new fact could not have been foreknown, if He did not know it, He did not know all. But only free beings' future actions and what depends on these are even prima facie beyond God's foreknowledge, and Scripture is full of claims that God foreknows free actions. If God's knowledge is perfect and includes complete foreknowledge, there is a sort of fact about which God's knowledge is complete and unchanging. Suppose that today God knows that I will finish this article tomorrow and tomorrow God knows that I am finishing the article. There is a fact God knows both days, that on this particular day, referred to one day as “tomorrow” and another as “today,” I finish the article. Such facts involve no real tense: they are ‘tenseless’ facts. If God has foreknowledge even of free creaturely actions, he always knows all tenseless facts. It is a small step indeed from divine perfection to necessary divine perfection. For it is surely more perfect to be unable not to be perfect than to be perfect but able not to be. Again, it is a small step from foreknowledge to necessary foreknowledge: the latter would be more perfect. (If knowledge must be “safe,” i.e. secure against error in varying conditions, one's knowledge in one respect better if it is safer, and it is maximally safe only if it is the case that necessarily, if p, one knows that p.)  If God's knowledge is necessarily perfect, His knowledge of tenseless fact is immutable.  In any possible world in which He knows a tenseless fact, He always knows it, if He is necessarily omniscient.  So it is not possible that His knowledge of it change, though if there are possible worlds in which it is not a fact, there are possible worlds in which He never knows it. Similarly, if God is necessarily omniscient, He immutably knows all necessary truths.