The Pursuit of Holiness by Jerry Bridges
I consider this to be one of the best Christian books out there. It is a call to holy living. Simple to read and well written. It is also on CD.
Understanding the Times by Dr. David A. Noebel
This book explores the differences between Christianity, Marxism/Leninism, and Secular Humanism. The updated version added Cosmic Humanism. Dr. Noebel uses quotes from each of the viewpoints to make his point. This book has more references than any other book I have read. It is extremely thorough and very well written.
Tortured for Christ by Richard Wurmbrand
A personal journey of torture, starvation, brain-washing, and humiliation by a government bent on keeping him from sharing the gospel. This is a clear picture of true persecution. It is a wake up call to those of us who never had to experience this level (or anywhere near it) of persecution for the name of Christ.
A Call to Discernment by Jay E. Adams
In this book Dr. Adams shows ways in which some people are lulled into bad judgement and explains how they can keep from being tossed to and fro.
Fearfully & Wonderfully Made by Dr. Paul Brand & Philip Yancey
Describes some of the incredible ways our bodies are made and function, and relates it to our spiritual maker.
Decision Making & the Will of God by Garry Friesen
Friesen explains that decision making is not so much about supposed open doors but about being in the will of God. A very different perspective than what is generally taught.
Peace Child by Don Richardson
Don Richardson tells about his family's missionary journey to the jungles of New Guinea. The people there, in a stone age culture, gave honor to treachery, yet their culture also had some strange similarities to Christianity that were used to bring those people to Christ.