This question by bjkeefe brings out something that struck me during your discussion of such a miracle. Wouldn't the miracle lie in that the arrangement of stars and the linguistic content of a message that is spelled out in the sky would be causally disconnected? It doesn't have to be that meaningful, emotionally, to have a similar effect (as Dr. Murray seemed to suggest). For instance, it would be just as shocking to find the first recipe in "The Joy of Cooking" as it would to find Gen. 1:1.
I think this is why the, apparent, predisposition for belief in non-physical minds doesn't, for a skeptic, have the same weight that as such a miracle would (the fact of such predispositions and the fact of wide-spread religious belief can be explained plausibly in a cause and effect way).
At another point
, Dr. Murray seemed to suggest that we have no empirical reason to believe in other minds (whether God or Maude). This strikes me as absurd. While it's true that we don't experience other's minds in the same way we experience our own, this does not entail that all of the expectations which come with such an assumption hold vacuously. For instance, I find that assuming internal motivations cause people to act more or less in the manner in which they do. As such, I assume that if I am given access to another person's motivations that I can more or less predict what they will do. This seems to work, with some reasonable margin for error. So in this way people test their naive theories of mind, in a manner which from my perspective is completely different from what people expect from a theory of God's mind.
If the bar for a theory of mind is to actually experience another person's mind (whatever that means), then I think it's fair to ask, why? We don't require that our theory of bridges be so robust that an engineer actually experiences the world as a bridge.