"Who's at the door?" book review

It's rare for me to read a book in under a day. Honestly, I can't recall the last time I did that--until I read "Who's at the door?" by Dan Harrington.
The subtitle of the book is "A memoir of me and the missionaries"--and that is what it is. It's more than just a one person's dealings with Mormon (LDS) missionaries, it is also a book where Dan explores his own belief system--and why he believes what he does.
This isn't a typical conversion story, but almost a "work in progress" as Dan searches for understanding. He asks questions I'm sure most of us have asked, and then either excepts or struggles when the answers don't fit into his previous beliefs.
While this book has highly spiritual overtones, it is also very funny. Dan has an excellent sense of humor and I found myself laughing more than at any recent movie or TV show in recent memory. He certainly is an excellent writer--and knows how to keep a narrative flowing.
There were surprises throughout the book, which I don't want to spoil, but that got me, as a lifelong member of the LDS church, to ponder.
There is so much more I want to reveal about the book, but I fear in doing so, I will ruin the experience for other readers.
So, who would enjoy this book? Well, it isn't just for Mormons. In fact, I can think of a dozen or so non-Mormon friends I'm going to whom I'm going to recommend this book. Granted, members of the LDS faith, especially those have served missions, will get an extra kick out of the book. There is so much as Mormons we take for granted, and it was refreshing to see our church through Dan's eyes.
I honestly hope two things for Dan. Number 1: that he finds the answers to his questions and lives a happy life. Number 2: That he writes more books--and soon.