Conversation so far:
Did Anberlin release any Christian albums?
No Christian albums specifically were released by Anberlin. However their music does contain Christian themes.
Does Anberlin identify as a Christian band?
Stephen Christian has said: If it (our music/albums) help people in whatever circumstances they're in, that's amazing, but I definitely don't classify us as a Christian band.“

Question: Why are they classified as a christian band?
Self-contained rewrite: Why is Anberlin classified as a Christian band?