In the general conclusion, I discuss the consequences of the textual analyses for the overarching theme of the book—how purity and defilement are redefined in early Christianity to support the theology, demonology, and understanding of human nature found in second- and third-century communities, and to construct the identity of these communities. I compare different areas of purity discourse (sexuality, dietary laws, asceticism, baptism), and trace the historical development of purity concepts and ideas through the first three centuries of Christianity, underlining the unique place of Origen and of Jewish-Christian communities in this development.