Many societies, shaped by culture, religion and tradition that have grown over centuries, are transforming into multi-cultural and multi-religious societies. Logically, religious communities are also strongly affected by these demographic and cultural developments. Co-operation between different religions and confessions becomes increasingly important. The articles in this volume take a closer look at a number of developments in inter-religious co-operation. What challenges and opportunities do such collaborations offer? What are the benefits of interfaith dialogues and common actions? This collection of four essays addresses those questions using different scales of analysis and specific examples of inter-religious initiatives and dialogue. The first essay focuses on how Christians deal with the challenges of Islam in Europe. The second article illustrates the considerations taking place, how the presence of people of other religions and beliefs affects the form and order of church rituals in Scandinavian countries. Interreligious co-operation in Europe is the focus of the third contribution which documents and assesses efforts to build a council of religious leaders at the European level. Entitled „Religions as Civil Actors. Current global strategies for inter-religious co-operation”, the fourth essay analyses the current priorities and strategies of this global network which are a plea for an active and committed formation and promotion of peaceful coexistence and a responsible lifestyle within the worldwide context of the current ecological challenges. These articles are intended to provide an overview for interested readers and for those who are already involved in this field as well as information, contacts and opportunities to connect.