The missiological strategies developed in the Middle Ages by the adherents of Judaism, Islam, and Christianity were centripetal in approach, drawing persons inward to a central structure. Multiplex institutions—kahals, zawiyas and monasteries—were constructed as outposts for the spread and/or maintenance of these religions’ respective beliefs and practices. In addition to the standard religious structures were collections of religious documents – libraries, in other words – that served as repositories for both Scriptures and other spiritually-oriented information. Those who made use of such collections added to them and in their comprehensive form they served as resource material for the education of successive generations. In this essay the origins and histories of the Jewish kahals, the Muslim zawiyas and the Christian monasteries will be explored with particular attention paid to the role played by the document collections in each. The authors will show how these institutions operated on the basis of a combination of both centripetalism (i.e. “coming in to a center”) and centrifugalism (i.e. “going out from a center”). The Muslim zawiyas and the Christian monasteries were intentionally spread throughout their respective regions as “missionary outposts.” The Jewish kahals were spread less intentionally but served in certain cases as “advertisements” for Judaism. All three institutions played vital roles in shaping, maintaining and spreading their respective religious beliefs and practices, and their equivalents can still do so in the present day.