Kynaston has explained this very clearly and I don't think he needs to apologise for anything. Religion is a very important factor in nomenclature, not only for Jewish names. Some examples - Makkawi is an Arab surname; if I were to explain it I would have to point out that it is a Muslim name. Yuhana, Shidyaq and Khuri are also Arab surnames, but any explanation would be incomplete that did not describe them as Christian Arab names. Popov , Popovic, etc., are Slavic surnames of the Orthodox community, not Catholic or Protestant. When the Jews of Germany were made to take permanent surnames in the late 18th century they often adopted existing German surnames. But sometimes those names had a different meaning for Jews; Sachs is one example. As a German surname it meant someone from Saxony; as a Jewish surname it was adopted in commemoration of martyred ancestors. Sachs stood for ZKS, Zera Kodeshim Shemo. Some names are Jewish - not Hebrew, not Yiddish, not Israeli - Jewish.