Barlygurl, death metal is so named for its fixation on the topic of death, and though "christian death metal" may sound contradictory, the terms "christian" and "death" go well hand in hand together. Bands preforming this genre focus on the dying of our flesh, and all worldly lusts and sins, as well as the death of Jesus Christ and the blessing of life and forgiveness it has brought to us. Hopefully that can give you some clarification.