Here are two books on prayer that have challenged and helped me: Fresh Wind, Fresh Fire , by Jim Cymbala, Senior Pastor of the Brooklyn Tabernacle. I read this book several years ago, and it's still working on me. Few books have challenged me, convicted me, and excited me like this one. I've got a stack of books that I'm planning to read, but they will have to wait because I'm going to re-read Fresh Wind, Fresh Fire first. The Power of Crying Out , by Bill Gothard. This book surprised me. I've been to Bill Gothard's Ministers Seminars before, and I never expected him to write a book about crying out to God. I was taught to pray with intensity from my childhood, so I enjoyed reading something that lines up with my experience. I once heard a sermon by Joseph Stowell, former President of Moody Bible Institute in Chicago, in which he also spoke about the benefits of learning to cry out to God.