This special issue of «Genesis» analyses, from a gender-sensitive perspective, the impact of crossing confessional and religious borders, of mobility, and of voluntary migration on definitions (and/or self-definitions) of religious identity. Against the backdrop of recent historiography on the mechanisms of the discursive structuring of space on one side and on global entanglement on the other, the authors tend to overcome a fixed delimitation of religious borders. The essays contained in this special issue present a series of case studies that range from the medieval era to the present. They investigate the strategies used to adapt to a new context, the conflicts generated by the encounters between different cultures, and the estrangement provoked by confrontation with a different culture. Analyzing the effects of mobility permits the authors to examine religious practices that assimilate into or differentiate from new surroundings. The specific focus taken here helps us to reflect on the “performative” aspects and fluidity of the construction of religious identities.