I know there's been a lot of suspicion about the Potter books, particularly among Evangelicals, and I respect the caution about popular culture that engenders that suspicion. But I think O'Callaghan makes much the better case.
Finally, the mythic symbol of Dumbledore is the phoenix, again a medieval symbol of Christ because of its ability to rise from the ashes on the third day after it has been consumed in a holocaust. It is the phoenix that comes to Harry in the Chamber of Secrets, when he recalls Dumbledore’s promise to remain at Hogwarts as long as someone there thinks of him. The phoenix gives to Harry the gift of the sword of Godric Gryffindor with which he will slay the Basilisk. The name Godric is a pre-Norman Conquest English name that means “the power of God.” So we have in the scene the association of two symbols of Christ, the phoenix and the griffon. And the gift the phoenix gives to Harry is the power of God, the power of Christ, to slay the basilisk, a symbol of Satan.
In short: Hogwarts is not a school of sorcery and the occult mastery of nature. It is a school of virtue, a community of inquiry in pursuit of wisdom, an academy of philosophy.
Predictions about the direction of the Potter books has been a hazardous undertaking up to now, but I'll place my bet now that Dumbledore is coming back in Book 7. The symbolism of the phoenix is too strong to lead anywhere else.