Yeah, I don’t think I’ve ever heard “blood traitor” outside the HP books/movies, but “traitor to his blood” is sometimes used to describe someone considered a traitor either to his ethnic group or his family. “Race traitor” is probably more common as a term for someone perceived (by racists of their own race) as being too supportive or fond of the “enemy” race.
The use of the term “blood traitor” is more akin to the term “n****r lover”, IMHO.
People using that term weren’t claiming that the Weasleys weren’t pure blood. They were saying that the Weasleys were “traitors” to the bigoted pure blood ideal.
It’s much like the way that the Westboro Baptist Church never claims that the soldiers whose funerals they picket were actually gay, but instead calls them “fag enablers”.
Hagrid was ridiculing the mindset that those who don’t share your hate become your enemy.
I don’t think Rowling ever mentions the Potters’ religious faith, if any, but the use of that verse doesn’t necessarily mean that the deceased were Christian. We don’t even know if they picked it themselves, or if it was chosen for them by next of kin or other grieving wizards.
While I agree with you on the in universe issues, Rowling is a practicing Christian and I doubt she had the Potters as anything but Christian.
Thanks! I’ve been wondering that for a while, but I’ve only read/seen the UK version.
Can I just point out that nominally religious schooling is the norm in the UK- I believe it’s actually required for state schools to offer regular (daily?) ‘communal worship’, normally in the form of a morning assembly. All my schools had one of these daily- a teacher or guest speaker would say a few things, generally vaguely religious or ‘inspiring’, or we’d all sing some hymns (or, in one school, ‘Puff the Magic Dragon’, possibly because that was all one of the teachers could play on guitar). They were largely used as an opportunity to give out prizes and make announcements to the whole school.
The fact Hogwarts doesn’t have any kind of regular assembly incidates to me that religion is not important to wizards at all. Being from the UK, leaving that out would have been a conscious decision, it’s so much part of normal British schooling. I can’t think of another book about English school, set in the modern era, that doesn’t feature assembly.
I’m not Christian, or religious, and I’m a little confused about this issue. I’ve always assumed wizards would be pagan, if anything. Isn’t believing in magic counter to Christian faith?
nm
That’s muggle prejudice.
It’s just a story, and it’s ‘magic’ like a child’s imagination, not ‘magic’ like pentagrams and calling up the devil for a chat. It’s only the religious fanatics who’ll go apeshit over a novel. Sadly, there seem to be more over here than not, and so Rowling could write her books in Britain, shielded from insanity.
Indeed 
The problem is that you’re assuming that the books offer the same sort of consistency that reality does. They’re fiction, people. Rowling throws in references to Christmas in a vague secular way because it’s a part of modern British society. If you examine the society of the wizards in the Harry Potter really carefully, you can find lots of contradictions. Rowling had no intention of discussing the religious beliefs of anyone in the books because she considered it to be a distraction.
Reality has plenty of (apparent) contradictions. You have to look longer and closer to find the consistency. Since there’s a limit to how closely we can directly examine fiction, that’s where fanwanking takes over.
appleciders-
the weasleys are absolutely purebloods. it’s mentioned not only in chamber of secrets but in every other book in the series. they’re referred to as blood traitors by some because they don’t care about blood status. in order of the phoenix it’s even mentioned that they are distantly related to the malfoy family (since there were so few pureblood families left, they were pretty much all related to one another). blood status is determined by parentage- hermione is a muggle born (called mudblood by some) because she has non wizard parents. harry is half blood because his father was pureblood and his mother was muggle born. ron is pureblood because both his parents are pureblood wizards.
To a bigot, a “blood traitor” would be even worse than a mudblood. A mudblood, well, they can’t help it, it’s not their fault their parents were trash. But someone like the Weasleys, though… They had the opportunity to be great, owing to being purebloods and all, but they choose to throw that away to deliberately sully themselves with dirty Muggle-borns.
Or at least, so the “logic” goes.