We are accustomed to talking of church and state, and a whole series of pairs of words that go with them lay and ecclesiastical, secular and religious, spiritual and temporal, and so on. These pairs of words simply do not exist in classical Islamic terminology, because the dichotomy that these words express is unknown. They are used in the modern languages. In Arabic, they borrow the terminology used by Christian Arabs. They are fortunate in having a substantial Christian population using Arabic, and they therefore have a good part of the modern terminology at their disposal, in their own language. In Turkish, Persian, Urdu and other languages of Islam, they had to invent new words.
Bernard Lewis