Joseph Shaw Bolton 
Natural Religion [PDF ebook] 
The Ultimate Religion of Mankind

Driven by the dissatisfaction and turmoil in religion at the time this book was originally published in 1923, the author sets out a belief that all people have an inborn religion and investigates what the future of this religion might be as it changes from age to age. In the short chapters here the author reflects on the current trends in theology at the time and the history of Christianity.

This is an early critique of formalised religion and a simple advocacy of natural religion which is a glimpse into the basic philosophy of the early twentieth century.