Books like The Incredible Power of Prayer
Roger J. Morneau
The Incredible Power of Prayer is 127 pages, about 2 hours 20 minutes at 250 words a minute.
6 books to read next
How long each takes
Reign of God 7.6 h 
The Great Controversy 10.2 h 
95 Theses on Righteousness by Faith 5.6 h 
Companion to the Seventh-Day Adventist Hymnal 12.9 h 
From 1888 to Apostasy 5.3 h 
Preparation for the Final Crisis 3.5 h Bar height shows length. Estimated at 250 words a minute.