I don't see the point, I classify as Christian anyone who accepts the new testament at least partially and Jesus Christ as a central figure - That's where the etymology and semantics of the word "Christian" ("Christ...") comes from - I know it's debatable and we could be here all day saying how the new and old testament work together but I think following Jesus seems like the essential message and I wouldn't call someone a Christian if they only followed the old testament
Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you