Dr.Hahn writes about Saints and Angels by starting with a description of what a saint and angel are. He did use a lot of biblical references in that he shows that saints and angels are explained and revered in the Bible. He uses a lot of the New Testament especially St.Paul in talking about angels and more importantly saints. I got a lot of feel of what St.Paul thought and wrote of/about saints.
Dr. Hahn includes chapters of 12 saints which includes the Virgin Mary, St.Michael and several Saints that Dr.Hahn loves and reference to for example St.Thomas Aquinas and St. Josemaria Escriva, in how that shaped his faith.
I highly recommend this book.