I just read up on that following your post, and it looks like they're Christian, but not a "Christian band":
Eight days after publication of the Guardian article, Joseph Bruce Tweeted "I think [it's] crazy how some press say we're a Christian band and act like we're all religious [...] I'm proud that we believe in God but I haven't been to church since I was like 10. I don't even know if [Utsler has] ever been to church!"[134][135][136] Christianity Today writer Mark Moring also challenged Ronson's characterization, writing that "The guys in ICP haven't used the word 'Christian' or 'evangelical' [...] so let's not call them anything that they're not claiming for themselves".
Insane Clown Posse - Wikipedia, the free encyclopedia