This book is really a text book for anyone involved or interested in Christian counselling.
Both the authors teach the subject at a theological seminary in the States.
Their influences include Jay Adams, a leading Christian psychologist, and Francis Schaeffer.
This model of psychology is very much more prescriptive than anything in secular counselling, or in many Christian circles, but the authors are consistent in their approach and they have been teaching the material for many years.
There are good appendices to aid the reader.