G. K. Chesterton 
Orthodoxy [EPUB ebook] 

Chesterton states that the purpose of his book is to attempt an explanation, not of whether the Christian faith can be believed, but of how he personally has come to believe it. In it, Chesterton presents an original view of the Christian religion. He sees it as the answer to natural human needs, the "answer to a riddle" in his own words, and not simply as an arbitrary truth received from somewhere outside the boundaries of human experience.