'Sin bin' isn't exactly religious now. :-) English speakers tend to define the word 'sin' in terms of one particular religion, but use it a bit more broadly. So part of what you and others are seeing is simply usage conventions. In Old English, the word 'synn' meant a crime - it wasn't originally religious. The Latin it was used to translate had a sense of being a religious error. That wasn't present in either the Greek or Hebrew, both of which used an archery term. So non-religious term (H, G), religious (Latin), non-religious (OE), religious (KJV on). Yes, it's confusing. %-) But there's nothing stopping us from using 'sin' in discussions outside of religions. Usage for morality/immorality is heavily tied to codes of conduct and right/wrong thinking, often with a strong black/white dichotomy. (Examples otherwise welcome.) Many religious traditions which include a concept that's sometimes translated via the word 'sin' aren't that dualistic. Personally, I don't care for either word. Both have far too much baggage and tend to lead people to think that there's common understanding when there isn't. 'Chet' in Judaism is very different from Christian concepts of sin.