John Butler 
Wonders of Spiritual Unfoldment [PDF ebook] 

A personal account of searching for spiritual understanding initially outside Christian teaching, this book takes the position that there are as many ways to God as there are paths up a mountain. Interpreting his own spiritual breakthroughs, the author describes them as "windows of realization" and likens them to the sensation of being made whole. The book describes his journey from Eastern mantra-style meditation to the Orthodox "prayer of the heart" and details how a love of nature and a desire to do good played an important part in his spiritual unfoldment.