Also, here is a short list of some christian metal bands that are quite decent imo: Impending Doom for deathcore (their earlier stuff is better than the new stuff imo), August Burns Red for metalcore, Renascent for blackened death metal, skillet for hard rock, theocracy for power metal, and there's probably more out there, but those are the bands that I listen to still, that really are christian.
Renascent in particular is the band that got me into metal, they put whole Bible passages into songs, and they made a song where the lyrics are my favourite psalm, psalm 139.