The book "The Christian's Mission in a Godless World" by Madeleine Delbrêl offers an in-depth exploration of the role of Christianity in an increasingly secular society. Originally published in 1957, this text is presented here for the first time in complete English translation. The author reflects on the challenges arising from encounters with Marxism and provides valuable insights and suggestions for Christians living in a world that often seems godless. The text is complemented by a correspondence between Delbrêl and her Marxist friend, as well as additional chapters that serve as a "foreword" and deepen the theme. The appendix highlights the inexhaustible possibilities that arise for Christians in such an environment. This book is not only a historical document but also a practical working tool for anyone seeking to engage with questions of faith in the modern world.