Editorial Part One: Humanity on the Move The Century of Cities: Pathways Towards Sustainability 13 DIRK MESSNER Part Two: Theological Reflections on Urbanisation and its Challenges Christians as Troublemakers in the City: Initial Experiences and Visions on the Value of Christian Faith for Shaping Society 25 MARTIN EBNER Learning to Live a Life of Hospitality: Theological Foundations for Proclaiming the Faith in the Cultural Plurality of Big Cities...