As I understand it, Diakonia Studies: Critical Issues in Ministry is a kind of updating and commentary and clarifying and restating of Collins’s earlier work on this subject. If you want to figure out this book, carefully read the introduction.
And wow, I can see now why Collins’s works come up so much in the recent secondary literature on deacons. He does a ton of primary source work that leads to unconventional conclusions. And if he’s right, that many of us are operating on a misunderstanding the diakonia word-group, then this is a really big deal.
I wish I could write a full-review, but I really need to just get on with appropriating his work. I’ll just say that while there are conclusions in this book I disagree with and arguments that I find week, most of his major points seem right and help answer some common and thorny questions surrounding the office of deacon, among other things. And I’m so thankful for the amount of work he’s done on this topic, both inside and outside the Scriptures. Lots to think about. I’m really glad I read this.