Franklin Hall (1907–1993) was a major influence on the Pentecostal and Charismatic revivals of the mid-20th century. Unbelief and the Power of Prayer | PDF | Jesus - Scribd
While the physical book is often treated as a rare pamphlet, you can find various editions and modern reprints: Because of Your Unbelief: Hall, Franklin - Amazon.com Because Of Your Unbelief Franklin Hall Pdf - Google