Following public discussions and scientific debates about the relationship between society and religion, it is commonly accepted that religion is a significant factor causing and/or intensifying conflict between groups within modernizing societies (Fox 2004). This general assumption applies to the Catholic and Protestant Churches of various denominations in Europe, but also to the Orthodox Churches in the Eastern part of the continent. Here, the main assumption is that the latter `have retained the loyalty of larger proportions of their respective national populations and have remained more uniformly conservative and more connected to nationalism.` (Ramet 2019: viii) Hence, these actors often represent obstacles to a further modernization of society, a development strongly favored by other major, secular-oriented groups like the younger generations. On the other hand, it was emphasized that the attitudes of religious leaders on the topic differ widely. Which structures characterize relationships in the sphere in contemporary Eastern Europe? Which developments between religion (religious communities), politics and society lead to certain dynamics contributing to integration or to conflict within the societies of Eastern Europe? The seminar intents to give an overview of contemporary sociology of religion, the religious sphere in Eastern Europe, and the entanglement of major religious communities with politics and wider parts of society, which contributes in identifying sources of conflict (as conservatism, nationalism, and intolerance), but also of a sustainable, modern development of society, representing the other part of the same spectrum.