Books like A History of Christianity
Diarmaid MacCulloch
A History of Christianity is 1,161 pages, about 21 hours 17 minutes at 250 words a minute.
8 books to read next
How long each takes
Orthodoxy 2.9 h 
The Story of Christianity 9.9 h 
The Serpent and the Goddess 4.9 h 
Canaan Land 2.8 h 
Turning Points, 6.3 h 
Pagans and Christians 14.7 h 
A History of the Christian Church 11.4 h 
Enthusiasm 11.4 h Bar height shows length. Estimated at 250 words a minute.