The Trinity was a new doctrine that developed. This book is replete with nearly 300 footnotes, a section on the history of non-biblical words such as "God the Son", a great summary, and a comprehensive annotated bibliography. The author quotes historians and primary material for the proofs. He charts the step-by-step development of what became the Trinity in three general Father-Son questions, the Holy Spirit added as a person, and three persons in communion. This study details the how Christ became as a pre-existent second "person" in the godhead.
Very good book! The author did a wonderful job keeping things understandable even as near the ending chapters you can easily see how confounding and confusing the trinitarian philosophy and doctrine is.
The only reason I gave 4 stars is due to typos throughout the book. That may seem petty but there were some typos that could cause confusion regarding dates and where something fell chronologically that required you to go back and make sure you read correctly in another part of the book.
Nothing that a quick update and publishing on Kindle wouldn’t fix.