In Cur Deus Homo, Anselm provides an argument primarily in natural theology (as I understand it, anyway) for the proposition that the divine nature assumed a human nature for itself, without confusion of natures (modulo the Chalcedonian credo, then). The argument goes something like:
- Humanity should redeem itself.
- Only God can redeem humanity.
- Should-implies-can (roughly; you could also say, "If something to be done is right/good, then there is a way to do it").
- Therefore God could in some way exist also in human form.
I personally like and accept this line of reasoning, owing greatly to my preconversion acceptance of (3). In fact, my conversion came about in part because of the above reasoning.
Now I say "in part," in part(!) because I thought there was a way to adapt Anselm's argument to the question of the Resurrection. First, sometimes John 3:16 is translated such that it says "shall not perish" instead of "will not perish." I don't know the original Greek words there, so this is a gap in my reasoning, but the idea is that the Bible is saying there that there are circumstances in which we can say that someone should be resurrected. (The Bible also talks about a "right to be the children of God": John 1:12.)
Secondly, then, let us suppose (this is a hypothetical, but we who believe would discharge the antecedent re: Jesus Christ) that there was someone who was very good, perfect in fact. If this perfect person died, would we be able to say that this person should be resurrected? That it would be right and good for this person to come back from the dead? Then via (3) from Anselm's argument, we would get, "Therefore, it is possible for this perfect being to be resurrected."
And if it was possible, and appeared to be actual, why would we think it was untrue that it had turned out to be actual?
Or is Anselm's kind of reasoning too flawed in general? He was, after all, as far as I know, the one who came up with the first ontological argument. But I am attracted to that argument, too, so I don't know...