Arthur Conan Doyle 
The New Revelation [PDF ebook] 

This book is a discussion about spiritualism, religion, men, faith, and the afterlife, topics about which Doyle wanted his writing to be remembered for. It doesn’t read preachy, rather it comes off like a conversation with an open minded friend.
The book is broken into 4 main chapters which cover the topics:
1. The Search
2. The Revelation
3. The Coming Life
4. Problems and Limitations
Each chapter offers thoughtful opinions on the subject from the perspective of a person convinced of the reality of life after death. Each chapter flows well from the previous to come to a suggested but not forced conclusion.