Published in 2005, this book aims to capitalize on the then current fascination with angelic beings. This attraction to spiritual beings continues today but it is marred by a unhealthy curiosity with astralism, reincarnation, and other types of New Age thinking.
There was a book that came out in 2006 (Rhonda Byrne, The Secret) which encouraged people to find a mentor who could assist their positive thinking about their lives. These people would inevitably bring about whatever you desired. If you didn't get your deepest desires of positivity, you weren't being positive enough. It was circular thinking but many people read the book. Finding a mentor became the true search goal. Not fulfilling your desires for peace and self understanding. Unfortunately, this left people open to having their trust abused by charlatans passing themselves off as gurus.
This book falls into that category as well, but not by intention of the author who seems fair-minded and somewhat knowledgeable. Astell seems to want to introduce people to the wide variety of literary sources, beyond the Christian tradition which reveres angelic beings the most, to reveal Muslim, Jewish, Transcendentalists, Assyrian, Greek, Hindu, Zoroastrian, and theosophist literary allusions.
This is a richly illustrated book but because most depictions of angels are from the Christian tradition, it is what it is. There is a moral equivalence given to all the traditions when of course the most accurate depictions are from the Christian writings or Christian interpretation of the Jewish scriptures.
There are instructions on how to contact an angel to become your guardian angel. I would not recommend these last chapters to christian readers since Christians already believe they have a guardian angel as this was explicitly stated by Jesus himself in the Gospels.
Angels are essential to the christian belief system and Roman Catholics have as part of their dogma the existence of angels which is necessary as part of salvation. This is due to the message of an angel to Mary of Nazareth that a son would be born to her and if she agreed would become the Messiah for all mankind.
This book is written from the perspective of comparative world religions, which I have also done some study in. ( )