An examination of the oldest surviving Arab Christian manuscripts makes it clear that, in the early Abbasid period, the inculturation of Christians into the world of Islam consisted of two steps: the translation of the scriptures and other ecclesiastical texts into Arabic, and the production of original works in Arabic by Christians. The present article studies this process in its earliest development in the monasteries of Palestine in the period between AD 750 and 1050. It features, in particular, an analysis of the introductory chapter to a work called The Summary of the Ways of Faith to highlight the religious issues involved in the Christian response to the call to Islam in this period.