religion and ethnicity are two completly different things, exept in the Balkans obviously. Ethnicity is something that you are born with and religon is something that you've been taught to or you've choosen to be. If a Chinese guy gets baptised in Serbian orthodox church he won't become  Serb, he'll be an othodox Chinese guy. But unfortunately during the last few wars in the Balkans religion became part of one's ethnicity.