Religions can serve as both a resource and an obstacle to social participation and integration. The focus of systematic, historical, and empirical studies is on the social contexts and conditions that enable and promote the integration potentials of religion and religious groups. It examines the contributions that religious groups and communities can make to both individual and collective integration into society, to civil society, and to social cohesion. It emphasizes that religion belongs in the public sphere and that public religions facilitate social integration. Furthermore, religious communities can support the integration processes of immigrants and, even in contexts of strong marginalization, provide their members with a safe haven.