My dad is a born-again Christian and he threw out all his Black Sabbath records when he (re)converted. I started listening to classic metal in college, and I eventually had to ask my dad... "You threw out this? This is some of the lyrically-mildest stuff I've ever listened to." He just kinda shrugged, and admitted that he overreacted a bit, but this is still 100% the way lots of the evangelicals I grew up with think about anything that's not explicitly marketed as "Christian."