I'm going to second this opinion. You're not going to find an anime that's Christian in philosophy/religious doctrine. There are a decent number that use Christianity as a motif or setting however. Chrono Crusade is maybe the closest you'll get. Or you can go the Maria-Sama ga Miteru direction, which takes place at a Catholic girls school (but all the characters are lesbians, and it aired in an era when the Catholic Church was very anti-LGBTQ so.....)

Edit: Kids on the Slope has Christianity (or rather, being a Christian in Japan) as a minor theme, and it's historical fiction so it might be one of the most accurate portrayals of Christianity in anime.