This book was written in 1981 and, unfortunately, it hasn't aged well. It is loaded with unfulfilled sky-is-falling, doom-and-gloom predictions that look pretty silly in retrospect. I have great respect for Foster's other books, but this one is in desperate need of a rewrite -- with a lot less agitprop and a lot more spirituality.
I began reading this book in an attempt to live a more simple life and ended up with so much more. This book is not just about simplicity, and what that means to God, but even more so about the Biblical commands concerning "living simple, so that others may simply life". Richard Foster brought to light for me the passages in the Bible about the oppressed, the unloved, the homeless, etc. Foster also does not lay down mandates for all Christians, but instead, through his wisdom and life example, allows God to do the leading.