Man's Search For Meaning by Viktor E Frankl is a life changing book that everyone should read. The book is in two parts. The first is a description of Viktor Frankl's life and mindset in a Nazi Concentration Camp. He describes how finding meaning in the most grim of circumstances provides hope and a reason to live. The second half of the book is his theory and practice for "logo therapy" (existential therapy). For context's sake, Viktor Frankl is a significant player in the history of psychology and therapy, as he presented a different perspective than the well known Sigmund Freud. Frankl presents a theory of behavior and mind based on finding meaning in life. Freud's theory in contrast focused on motivational drives.
As a therapist I often recommend this book to clients that have suffered terribly from abusive relationships, drugs/alcohol, divorce, grief, depression, etc. What I find is that it leads to a sense of hope and accomplishment that we can (and do) overcome the most challenging and heart wrenching of experiences. Every time I read this book, I personally come away feeling in awe of the human spirit.