Who influenced you the most in the way you think?
I am an avid reader. You will learn a lot about me by knowing the authors I read the most - not that learning a lot about me is the important point but rather that you might look at these authors, too. Here is a list - the ordering is a rough measure of their influence:
God (through His agents who actually wrote the books)
Here are a few books that had a big impact on me. It's hard to pick just one from each, but here's a start:
C.S.Lewis - The Screwtape Letters. Fantastic insight into how Satan works. Tells us as much about ourselves as about Satan. A good, highly readable, book to start falling in love with C.S.Lewis' writing.
Ravi Zacharias - Can Man Live Without God. I remember sitting on the hotel balcony at Marco Island, Florida, reading this book with tears coming down my face. It simply touched something very deep in me. I believe it was the awakening of an awareness that we really were made for God and it could be argued successfully.
John Piper - God's Passion for His Glory. This is Piper's narrative (and most importantly his explanation) of Jonathan Edward's essay, The End for which God Created the World. The book showed me that God's passion for His glory is the measure of His love and commitment to our joy. God does things for His glory. That is the chief end (purpose) of all things. In terms of the day-to-day influence of how I view God, no book other than the Bible has had more influence.
Frank Peretti - This Present Darkness (fiction). Gave me a tangible understanding of the unseen spiritual warfare that surrounds us. This book almost makes the unseen visible.
Chuck Colson - The Body. Gave me an early vision of what the church could and should be.
Lee Stroebel - The Case for Christ. Though so many of the books/authors I read had something to do with apologetics, this book, and Lee's subsequent books, gave form to the practical apologetics for evangelism. We have a really good and sound case to make to the honest and sincere inquirer.
Norman Geisler and Frank Turek - I Don't Have Enough Faith to be an Atheist. Outstanding resource for the intellectually honest seeker or the Christian looking to discover the sound rational basis of faith in 12 progressive steps starting with is Truth knowable and leading inexorably to the Bible is the Word of God.