Despite the admirable “Licht vom Osten” of Adolf Deissmann and the more recent studies of Cumont, Bousset, Norden, and Reitzenstein, the student of the history of religions can still set his plough to much fruitful soil in the field of the papyri. Even the intensively cultivated domain of church history could be broadened and enriched by studies derived from such data in their application to problems of Christian institutional and constitutional development, of monasticism, and of the sociological aspects of the church's expansion. In another quarter, that of the persecutions, the papyri have helped to an understanding of the genre littéraire of the Acts of the Martyrs, and to a more accurate conception of the relations of Roman state and Christian church. This last we owe particularly to the finds of Libelli from the period of the Decian persecution.