Book that change us

I read a lot of interesting things, but most of them pass on into some lost hole of the mind; few could be said to be life-changing. And yet, valuable to some degree as it all is, I do treasure some books which I have read which changed my outlook and my behaviour.
I am rereading Surprised by Hope by Tom Wright, which deals with resurrection, and when I first read it it energised and excited me like nothing else. It's good, and I certainly recommend it and anything else by Tom Wright, but I don't feel the excitement I felt when I first read it.
I know that there are WEC books which have changed my life. Operation World is undoubtedly one. More recently, The Future of the Global Church, in which Patrick Johnstone outlines world history in the light of the growth of the church, and extrapolates from history to predict trends for the future, is another inspiring book which will affect the way I look at the world.

 Life Lessons has also had an impact on me. Published in 2010, this collection of chapters by different members of WEC relates one lesson that God has shown each of them in the course of their lives. This format led to a deeper and possibly more honest account of what was important for the writers. Although they are all different, there is a thread of slowing down, listening for God, living life in step with His pacing, and not trying to do God's work for Him.
What books have changed your life?