Dr. Davie gives a pretty thorough background and history of each of the 39 articles that are a foundational document for Anglican Christians. The meaning and nuances of each article are explored in depth. The historical and theological context for each proclamation are explained.
This book was very helpful for me as a Presbyterian learning more about Anglicanism. My only nitpick is that there is a lot of text describing the precise textual variants of each article in their first 50 years of existence. The creed went through a variety of transformations as the Reformation and subsequent movements refined their understanding of various topics and their reaction to Roman Catholic adjustments.