This book discusses inner peace from an Islamic theological and spiritual perspective, the writings of Said Nursi, a twentieth century Muslim scholar. Inner peace is a topic of great interest in the world at present. While happiness and mental health have been extensively discussed from a psychological and sociological perspective, and while inner peace has been written about from various religious viewpoints, there is very little scholarly work on inner peace from an Islamic theological and spiritual perspective. This book addresses this significant gap. With Islam being the second largest religion in the world, this book provides an important contribution to the literature on a faith tradition which is followed by so many. In addressing the intersection between Islam, spirituality and psychology, this book makes an original contribution to the literature on modern Islamic thinkers like Nursi, and to the broader fields of Islamic studies, and theology, philosophy and well-being studies.