This is the fourth of 17 posts, which are collectively Eternity, etc.
......As aforementioned, God is the ground of metaphysical possibility, if He exists. Let us assume that He does (if only for the sake of agnostic argument). (And let us also assume libertarianism, if only because Mawson’s arguments do). Since God is, presumably, the greatest conceivable being, we can again follow Mawson and say that He is omnipotent, where “an omnipotent being is a being with the most power-granting set of abilities that it is logically possible anyone might have”[i]. It seems to follow that God is infallible, since being able to make mistakes would surely detract from His overall power [ii]. The Open God might be epistemically infallible, for example, in virtue of His beliefs being held by Him only insofar as they are completely justified [iii].
......Does it also follow that God is omniscient (see previous post)? Each possible fact might be associated with a power to know it. But that might be a power to know it eventually. Would it be more power-granting for God to know now all that He will ever know, or for Him to be able to know anything desired as quickly as desired? It’s hard to say, but it seems that the most powerful God is able to increase His knowledge (see section VII), which would stop Him having what Mawson calls “complete omniscience”[iv], but would not obstruct His necessary omniscience (see section VIII).
......What is relatively clear is that God is eternal, i.e. without beginning or end. That is clearly so if God transcends even the possibility of change. But even the Open God is necessarily unending, because there should never be any real (metaphysical) possibility of the ground of all good things not existing. And if the Open God had some primary state, prior to all His other states, we might regard that as time having its beginning in Him, rather than vice versa (see section IV) [v]. So, God is eternal; what is less clear is whether He is timeless or everlasting. Indeed, even that question’s terms can be questioned.
......Mawson’s terms—“atemporal” and “temporal”—were not too bad, being less biased towards atemporalism (aka Eternalism) than were the traditional terms, “eternal” and “sempiternal” (following Boethius). But whereas both “timeless” and “everlasting” connote unfading immortality, “temporal” connotes limitation. E.g. it can also mean civil or secular, as opposed to sacred or spiritual. And crucially (see section IV), the Presentist Open God does not exist inside the sort of temporal dimension that the atemporal God transcends [vi]. To avoid begging the question, and to stay apposite [vii], I suggest that we call God “timeless” if He transcends, not only spacetime, but even the possibility of change, and call Him “everlasting” if He is so involved with us that the future is open (in the sense of Open Theism).
......[i] Mawson, “Divine eternity,” p. 41.
......[ii] For more details, see Mawson, Belief in God, pp. 28–35.
......[iii] For a possible problem with that, see Omniscience and the Odyssey Theodicy.
......[iv] Mawson, “Divine eternity,” p. 37. “A completely omniscient being cannot learn anything,” ibid, p. 41 n. 5.
......[v] See also William Lane Craig, “God, Time, and Eternity,” in Harry Lee Poe & J. Stanley Mattson (eds.), What God Knows: Time, eternity, and divine knowledge (Baylor Univ. Press, 2005), pp. 75–93.
......[vi] See also Alan G. Padgett, God, Eternity and the Nature of Time (St. Martin’s Press, 1992).
......[vii] I am ignoring immutable temporal Deities. And according to my definitions, God would be neither timeless nor everlasting if He was able to change but had already created our future (see note v of Possible Worlds).