What could the doctrine that all times are present to God mean?
Suppose you have a time machine that lets you travel through all of time in a finite amount of subjective time. How? Well, first travel back a thousand years; then slow down your internal time, so that you live through the millenium in half a second of internal time, or else fast-forward with your time machine at two thousand years per second; then travel back two thousand years, and then change your subjective time so as to live through that millenium in a quarter of a second (or else fast-forward); keep on going until all the past is covered. This will take no longer than one second, even if the past is infinite (if the past is finite, you need to adjust for the fact that the age of the world may not be a multiple of a thousand years, but that's a triviality). Now do the future, which is easier: just slow down your internal time to cover the future millenium in half a second, the next millenium in a quarter of a second, and so on (or else use your time machine in fast-forward mode). In at most two (subjective) seconds, you'll have covered all of time.
Now, repeat this process over and over, forever. Assuming your specious present is at least two seconds long (if it's shorter, just speed up the process and/or increase your mental capacity), all objective times will always be within your specious present. So here is one apparently coherent sense of the claim that all objective times are present to a being: all objective times are within that being's specious present. And the above argument suggests that it is logically possible to have a being such that all times are within the being's specious present. Indeed, it is possible to have a being such that this is always the case.
I am not claiming that God is such a time-traveler. For one, God is unchanging, while this being seems to live on a changing two second cycle. But we can get a bit of a help towards imagining of God's relation to time as follows. The above being goes through all of objective time every two seconds. We can imagine another being that does this every second. And another that does this every half second. God, then, is like the limiting case of this progression of beings.
What is helpful about this is that it suggests a way of understanding the idea that God's immutability is not stasis but infinitely fast activity.
