There's plenty of Christian metal bands. Zao, As I Lay Dying, Norma Jean/the Chariot, Thousand Foot Krutch, Living Sacrifice, Extol, etc.. Almost all of it is metalcore or nu-metal though. Christians don't generally touch death metal. Don't know why.. Yeah it's rare, some do though. Mortification is probably one of the first to do it, they're Aussie aswell. Then there is the black metal Christian bands such as Frost Like Ashes & Slechtvalk.