This review is from: Apostolate and Ministry: The New Testament Doctrine of the Office of the Ministry (Hardcover)
Concordia Publishing House has recently started a publish on Demand program so this book is still in print, and that is good news because its voice needs to be heard today.
Rengstorf says in the preface to the first edition "The only purpose of the discussions in this booklet is to make a modest contribution toward the creation of a new and healthy consciousness of office among our clergy." How needed that is today as mainline protestant churches more and more abandon the New Testament admonitions concerning who should and should not be admitted into the pastoral office. More and more people see the pastoral office as nothing but a job, and completely disconnected from Jesus' commissioning of disciples to "go and make disciples baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to observe all I have commanded you." It is not good when the people don't see the connection between the pastoral office and the apostles entrusted with the task of forgiving sins and retaining sins, (John 20). It is downright pitiful when pastors themselves don't see it.
Rengstorf also does much with his study of what it meant in the first century to be an apostle. The closest thing we have today is someone having full power of attorney. But that pales in comparison with the authority one entrusted another with when he made them his apostle. These men literally spoke for Jesus, when they said it it was as if Jesus himself said it. To question what one of Jesus apostle's said is therefore to question Jesus himself. Red Letter Bibles can no longer be used to pit what Jesus said against what the apostles say.
It is a great book, and should be part of any study of the pastoral office, or pastoral theology.