Book excerpt: This book offers a comprehensive exploration of key issues in contemporary global migration and considers the theological implications for Christianity, in general, and for Christian faith and practice in various parts of the world, in particular. Migrant Christians, who make up the majority of believers on the move and in diaspora, play an increasingly vital role in world Christianity today. Drawing on cases from across the globe, Gemma Tulud Cruz considers how Christians are faced with immense gifts and tremendous challenges brought by the ever-increasing presence of migrants in their midst and the conditions that characterize contemporary global migration. Migrant Christians themselves face multiple challenges, which have been made more stark by the coronavirus pandemic. The volume will be relevant to scholars of religion and of migration who are interested in a closer examination of what happens to Christians and Christianity, (faith) communities, and nation-states in the age of migration.