It’s interesting to see how intertwined metal and Christianity are.
Slayer? Singing songs about hell and has a crucifix at the concerts. But the singer is Catholic. He also notes Catholic services do the same thing.
Iron Maiden released a song called “The Number of the Beast” and got moral guardians’ upset despite being based on the Bible.
Avenged Sevenfold gets it’s name from the Bible (whoever kills Cain will get 7 times the retribution.) “Beast and the Harlot” is also a story torn from Revelation.
DragonForce refers to God a lot. It helps that most of the members are Anglican. In an interview Herman Li said that when they talk about “the master” and other such figures in their songs, they’re referring to God.
James Hetfield was raised a Christian Scientist. Didn’t go well, though.
Helloween has several blatantly Christian songs. Like “Save Us”.
Evanescence was considered a Christian band until they explicitly told the Christian records stores they were not. Stores complied when they swore in an interview.
Black Sabbath used the occult symbolism to sell records. Geezer is a Christian.
Some people try to convince themselves Marilyn Manson is Christian. Just look at Yahoo Answers. He is not, though.
Lots of people listen to Lamb of God thinking they’re pro-Jesus. That doesn’t last long.
There’s always fun arguing whether “Chop Suey” by System of a Down is about Jesus. Of course, calling Jesus’s spiel “self-righteous suicide” doesn’t end well.
Godsmack is in a similar boat to Lamb of God.
HIM is supposed Christian. And by supposedly I mean it stands for “His Infernal Majesty”.
Linkin Park does the occasional Christian song.
Attack! Attack! has Christian songs very forthright. Not a Christian band because some members aren’t.
Head left Korn when he converted.
We Came As Romans is mistaken as Christian because some of their songs have uplifting messages. I think some people want too badly for their favourite bands to share their favourite religion.
Flyleaf is a Christian band despite them saying they aren’t.
One time Judas Priest was set to play a concert for a audience of nuns. Someone didn’t do their research.
Twisted Sister stabs at it here and there.
There is also, of course, the entire genre of Christian metal. I at one point even made a playlist of songs. It’s a bit tilted towards power metal. August Burns Red and As I Lay Dying are rather popular even in the metal mainstream. (Divinefire not so much.)