A group process is not a linear process. And the development of the group is different from the development of the individual group participants within it. Both dimensions intertwine, especially when it comes to a semi-open group. The individual phases of group development, from initial fears and projections to more trust and confidence, but also to increased conflict resolution skills, are relatively well described (see Yalom, Theory and Practice of Group Psychotherapy. Klett-Cotta, Stuttgart, 2016). However, there are also destructive developments in groups that deserve attention (see Nitsun, The Anti-Group. Routledge, London, 2014). No group is self-sustaining and will only bring about beneficial and creative aspects. It always involves the acceptance of the shadow, the acceptance of loneliness, of emptiness, of anger and destructive desire. We will get to know the concept of the “Anti-Group” and how well it is suited to describe the polarity of development in and of groups. Various fears, which can revolve around injuries, shame, and sexuality, must first be recognized before they can block the group process less strongly. Communication is something that every group must develop and build anew, always with the help of the personal resources and also limits of its members. Beyond all resistances, there are also archetypal forces that have a positive influence on the group process. These forces and the question of how they can be used by the leadership of a group will be examined in more depth in Chap. 14 and 15.