Christian in what sense?
Lol
There are some priests and crosses in Castlevania, does that count?
Anime treats Christianity about as seriously as it treats Buddhism or any other faith, which is to say not at all. There are comedic takes like Saint Young Men, some exorcist stuff like Vatican Miracle Examiner and the priest character in Ghost Hunt, and occasionally someone will take a look at the history of Christianity in Japan (for instance, the Christians Arc at the beginning of the third season of the original Rurouni Kenshin). If you’re looking for something that’s Christian in philosophy, you aren’t going to find it.
Saint young men or Maria-sama
In the Beginning is an anime that follows the Christian old testament up through the birth of Jesus.
There’s also Superbook about 2 kids and a robot who time travel to bible times get involved in the biblical events.
This is what I thought the OP meant.
Castlevania, I guess? The english dub gets pretty bad, just a headsup.