A.W. Tozer wrote a number of books, but the one that he is most well known for is a small book called "The Knowledge Of The Holy". Tozer was known for his deep passion for the majesty and holiness of God and He saw the world's problems as symptoms of bad theology.
The opening statement of chapter one tells us a lot about what is in the book: "What comes into our minds when we think about God is the most important thing about us". The remainder of the book is written to draw the reader into a deep worship of The Almighty; and it does this very well.
I came across this book in the winter of 2002 and it has been one of my favorites ever since then. It opened my eyes to the importance of accurate theology. There are books that connect better at one season of life than another, but this one has been relevant to every season of life I find myself in.
There is still a desperate need for believers to develop a high view of God. He is much more holy and mighty than we can ever imagine. If we don't have a high and accurate view of who God is, we won't have much appreciation for Grace. The carelessness that people approach their faith with is the direct result of bad theology.
Tozer also addresses the tendency of humans to create an idolatrous picture of a God that they are comfortable with, and then worship the picture instead of worshiping God. If you don't think it can happen to you; you don't know your own weaknesses. We tend to read the Bible and capitalize on the parts that fit our view of God and ignore the ones that don't fit. A Biblical view of God will always disrupt our lives and where a life is unaffected by God it is probably not worshipping God at all.
I highly recommend this book as one that should go on your "must read" list. Don't ask to borrow mine. Get your own copy and keep a highlighter handy.