Children and adolescents experience rapid changes due to development and growth processes, thereby necessitating adaptation and flexibility. In addition, young people also often face environmental crises or traumas, human-made catastrophes, or individual (chronic illness) or family (parent divorce, death of a loved one) crises. In the past, to facilitate young people's adaptation to change, major aims of parents, teachers, and therapists focused on protecting children and adolescents from harm and helping them grow up in a secure environment. Over time, modern life and the influence of the positive psychology orientation have led to a shift in those aims, which now focus more on helping young people feel happy, flourish, and use their own strengths. A key element in making this process of adaptation to change successful is resilience. This chapter deals with the effects of changes, crises, and traumas on children and adolescents, while focusing on the importance of resilience at the individual, family, and environmental levels. This approach directs adaptation to change efforts towards the present rather than towards the past, thereby meeting the important need of treating children and adolescents who have experienced crisis and trauma by imparting them with skills for better coping today in their major natural environments.