I have a problem with this one.
A Jew is a Jew is a Jew, don't let people think different, the labels are just window dressing.
And if you're not a Jew, you're a Noachide i.e. Son of Noah so that's everyone else.
But you're a Chrisitan you say? That just means you're a Noachide practicing Chrisitanity. Being a Noachide isn't something you choose to do, you're just born a son of Noah if you're mother's a son of Noach, just like you're a Jew if you're mother's a Jew. Most people don't understand this.
The only question is are you a "Noachide Chassid" i.e. a practicing or devout Noachide i.e you beleive in the whole Torah and committed to practicing you're part of it...the 7 Noachide laws.
P.S. Even Jews are all sons of Noah, we're just sons of Jacob also that's why we're called the children of Israel (Bnei Yisroel).