Abstract: At the microlevel, this paper focuses on the Roman Catholic cult of the Sacred Heart, noting its spread among Catholic populations in Central Europe whose liturgical tradition is that of Byzantium rather than Rome. At the mesolevel, it places this instance of religious acculturation in the context of long-term economic and political inequalities between East and West. At the macrolevel, implications are outlined for debates concerning civilizational differences and modernity. It is commonly supposed that the latter was initiated when Protestants began a shift toward interior belief based on text, eventually dragging Roman Catholics in their wake, while Eastern Christians have remained largely excluded from both material and ontological progress. The anthropology of Christianity has concentrated on Western-influenced “moderns,” in their many guises, outside the religion’s heartlands. But the take-up of Sacred Heart religiosity among the Greek Catholics of Central Europe suggests that there are no deep ontological barriers within Christianity. Similarly, there are no grounds for dismissing Eastern Christian institutional patterns as premodern; they should be drawn into the comparative framework as a distinctive crystallization of Christian civilization.