Instruct: Classify Amazon reviews into positive or negative sentiment
Query: The most thorough history of revival I've ever read

My first introduction to Dr Orr was a Campus Crusade for Christ film entitled "The Role of Prayer in Spiritual Awakenings". Though encouraged by the prospects of simply "praying" in a revival, I honestly felt the author's simplistic enthusiasm was unrealistic. After reading The Flaming Tongue's exhaustive report on the Welsh Revival, there has never been any doubt in my mind that Dr Orr was a first rate historian, and, his assertion that EVERY great awakening was preceeded by a world wide movement of prayer must be correct. Though the reading was excruciatingly dry history, the personal rewards were phenomenal. The Flaming Tongue convinced me that there must be a scriptural basis for this thesis, and I have since established a thorough scriptural basis for it. Without the sheer statistical force of Dr Orr's exhaustive works, however, I've found that most of my brethren simply refuse to believe that prayer brings revival.