One of their songs, "After Forever", is a composition the band wrote because so many people thought they were devil worshippers,and a passage in the song proves their true belief:
It's best you think before you say God is dead and gone
Open your eyes and judge for your life 'cause He is the one
The only one who can save you now from all the sin and hate.
There was one reason, also, why they used evil imagery on their album covers. It sold records. Period. Record executives knew that because it shocked and/or offended people back in the 1970's, and created a buzz for people to go and buy the album.
I don't remember saying anything about that.
Or just think of "Paranoia." That's a truly depressing song with nothing to do with religion or evil.
I didn't say anything about that, just that usually, the set of (fundamentalist Christian, even when very much on the fringe) and the set of (Ozzy Osbourne fans, to the extent that they know lyrics to many songs) don't usually overlap to any great extent. BTW I am a Bible thumper myself.