Horace Jeffery Hodges looks at Christian echoes in the Harry Potter books. (See here as well.) I had missed the "great silver cross". One of the key points of the cemetery, though, I take it, is that Voldemort tries to lay up his treasures on earth (the Horcruxes), where, of course, thief can steal, in order to destroy death; but those who oppose him treasure friendship which (as we see in the William Penn quote at the front of the book) is immortality before "that which is omnipresent" and therefore makes possible the triumph of love over death.
I think Hodges is right, incidentally, about Rowling vs. Pullman. Pullman is very clearly the better stylist; Rowling is at best inconsistent. But Rowling has far and away the better craft: Pullman is at least as inconsistent in his craft as Rowling is in her style. There's nothing wrong with that, since both are good to have, and few manage to be consistently excellent in both, particularly over several books. There's no question that Pullman is a skilled writer worth reading. But I think in the end it means that Rowling almost always hits her marks whereas Pullman hits nothing. Rita Skeeter is finely crafted to be a commentary on journalism, to take one small example of which the books have many; but nothing in Pullman's story is like this. Pullman's Magisterium is nothing like a Church, being utterly insane, and therefore cannot pull off the intended commentary on churches in general as things that "control, destroy, obliterate every good feeling"; we learn nothing about good or evil from Lyra and Will, and certainly not from the death of God, which makes no narrative sense. Part of that is due to the fact that Pullman has little more than a basic sense of narrative himself; it's why he subscribes to Blake's notion that the imaginative sympathy in Paradise Lost is with Satan, despite the fact that virtually everything in the poem is constructed so as to show that Satan is a liar and the Father of lies, who cannot even talk to himself without obviously lying, and sometimes contradicting himself, in an attempt to make himself seem bigger and more important than he is. Part of it is perhaps that Pullman can't outmaneuver Milton, for all he makes a valiant attempt. In Paradise Lost, Satan, too, is chiefly a literary stylist; it is God who has the skill of a storyteller. When Milton is the major influence, a story from the Devil's point of view will inevitably be stronger on style than storycraft. God, being Almighty, can let the tale unfold, unworried about the outcome, but for Satan to be the victor in a battle against God, the story has to be rigged, and Pullman manifestly does rig it.
But in Pullman we get a very rich style, Miltonic and at least more-or-less consistent, full of rich description and beauty. Rowling's not bad at it, but her style is far simpler and considerably less consistent. Similarly, Pullman's not horrible at storytelling -- we do get genuinely interesting bits of storyline -- but he's not nearly as consistent at it, or as frankly clever with it, as Rowling is. Rowling may seem simplistic to the superficial reader, but she can be beautifully subtle. As an example, most readers come away thinking Harry destroyed two Horcruxes. But he didn't; he only destroyed one Horcrux himself. Someone else destroyed the other one that most people attribute to him -- and it's the only person who really could have, the most narratively appropriate person possible, so that, setting aside the Horcrux destroyed by accident (but, notably, by the ones most closely associated with the room in which it was done) each Horcrux was destroyed by one of the six people in the whole world that the whole preceding storyline had shown to be the most dangerous to Voldemort. And the fact that she recognized the suitability of one of those six, and that that one had to be that one, was not just a good sense of narrative, but a sheer masterstroke of storycraft. Pullman has some beautiful subtle descriptions, but nothing remotely like that. People often make jokes about Pullman's plotting; no one could honestly do the same with Rowling.