The Self-Donation of God, chapter 8:
"Modern theology (beginning with Schleiermacher, whom we will discuss below) has generally been uncomfortable with these categories of thought. This has been the case for several reasons. One objection comes from the Liberal Protestant historian of dogma Adolf von Harnack. Harnack derided the Church Fathers for their use of philosophical categories taken from Platonism, Stoicism and Aristotelianism. He viewed this as being the essentially downfall of Christianity. The intellectualizing tendency which use of these philosophical traditions represent, degraded Christianity into abstract philosophically belief system from its pristine origin as a religion of the heart. In essence, then, for Harnack, true Christianity is tied up with ethical uprightness ("brotherhood of man" and "fatherhood of God") and the interior experience of the divine that does not need theological abstractions such as the Incarnation or the Trinity.
Regarding Harnack's treatment of the Church Fathers, much research has shown that his thesis is not accurate. The newer scholarship has demonstrated that as a result of theological debates and Church-usage, much of the Greek philosophical terminology that the Church Fathers borrowed was significantly redefined. In fact, sometimes the terminology was modified quite radically in light of the newness present in the biblical teaching. In this vein, Luther in some of his later writings spoke similarly of the "new language" (nova lingua) of faith. In speaking of the nova lingua, the Reformer noted that words take on new meaning through events of revelation. Quiddities like "divinity" and "humanity" are mutually exclusive in normal (or philosophical) language, but when we come to discuss the Incarnation they are not.
Adding to this point historically, the patristic scholar Robert Wilkenson, has also noted that the Church was in fact instrumental in developing its own unique grammar for dealing with Christological and Trinitarian realities. Ultimately, such language (and the ontological presuppositions that came with it) developed in debates because interaction with the biblical texts. Such debates were of course influenced by Greek philosophical presuppositions, but as the discussions progressed many of these presuppositions were greatly changed by interaction with the biblical material or even eliminated."
The Self-Donation of God, chapter 10:
"Although some theologians (notably Werner Elert and Wolfhart Pannenberg) have criticized this schema of the threefold office (triplex munus) first introduced into Lutheranism by Johann Gerhard, it is necessary for understanding the work of Christ. First, as we have shown in our extensive exegesis in the preceding chapters (which we will not repeat here), the threefold office of Christ is thoroughly biblical and is not something arbitrarily imposed on the text of Sacred Scripture. In fact, as we have seen, this schema is used repeatedly not in just a few biblical texts, but is pervasive throughout the New Testament and prophetic writing of the Old Testament. Because of its presence in the Old Testament, the Second Temple Jewish expectation of multiple Messiahs to fulfill these multiple offices makes a great deal of sense. Secondly, because Christ fulfilled the threefold office given to Israel and Adam, the threefold office is also useful for emphasizing the unity of God's works within the new and old creations. Just as God established human vocation in the beginning with Adam as the protological prophet, priest, and king, so too he elected prophets, priests, and kings in biblical Israel. Through the prophets he promised a coming Messiah would fulfill all these roles and that creation would be renewed through him. Finally God sent forth his Son to fulfill these vocations and bring about redemption. Recognizing this unity of divine agency in creation and redemption is useful for staving off the ever present threat of latent Marcionism.
Lastly, humanity is redeemed by Christ's fulfillment of the law through his active and passive righteousness. The law is not an abstract standard, but is fulfilled by human moral agents within concrete vocation within the created order. Therefore in order for the law to be fulfilled, Christ had to take up the human vocation as it had been established at the beginning of creation. Since the law is in fact identical with God's desired structure for the created order, fulfillment of the law by Christ as a divine-human agent is identical with the renewal and recreation of the world. Since the old structure of creation was mangled, it was necessary to recreate the world by a re-actualization of its original narrative and structure. If Christ were merely a man, his activity of fulfilling the law could not do this. Humans are not capable of creating anything by their actions, even if performed in obedience to God’s will. Nevertheless, since the activity and presence of the humanity of Jesus are identical with the divine person of the Logos, his human actions in fulfillment of the law were infused divine power and glory. By this human obedience, he did what only God could do and renewed creation. In order to accomplish this, Christ took over and fulfilled the offices of Adam, the protological prophet, priest, and king."
"Although some theologians (notably Werner Elert and Wolfhart Pannenberg) have criticized this schema of the threefold office (triplex munus) first introduced into Lutheranism by Johann Gerhard, it is necessary for understanding the work of Christ. First, as we have shown in our extensive exegesis in the preceding chapters (which we will not repeat here), the threefold office of Christ is thoroughly biblical and is not something arbitrarily imposed on the text of Sacred Scripture. In fact, as we have seen, this schema is used repeatedly not in just a few biblical texts, but is pervasive throughout the New Testament and prophetic writing of the Old Testament. Because of its presence in the Old Testament, the Second Temple Jewish expectation of multiple Messiahs to fulfill these multiple offices makes a great deal of sense. Secondly, because Christ fulfilled the threefold office given to Israel and Adam, the threefold office is also useful for emphasizing the unity of God's works within the new and old creations. Just as God established human vocation in the beginning with Adam as the protological prophet, priest, and king, so too he elected prophets, priests, and kings in biblical Israel. Through the prophets he promised a coming Messiah would fulfill all these roles and that creation would be renewed through him. Finally God sent forth his Son to fulfill these vocations and bring about redemption. Recognizing this unity of divine agency in creation and redemption is useful for staving off the ever present threat of latent Marcionism.
Lastly, humanity is redeemed by Christ's fulfillment of the law through his active and passive righteousness. The law is not an abstract standard, but is fulfilled by human moral agents within concrete vocation within the created order. Therefore in order for the law to be fulfilled, Christ had to take up the human vocation as it had been established at the beginning of creation. Since the law is in fact identical with God's desired structure for the created order, fulfillment of the law by Christ as a divine-human agent is identical with the renewal and recreation of the world. Since the old structure of creation was mangled, it was necessary to recreate the world by a re-actualization of its original narrative and structure. If Christ were merely a man, his activity of fulfilling the law could not do this. Humans are not capable of creating anything by their actions, even if performed in obedience to God’s will. Nevertheless, since the activity and presence of the humanity of Jesus are identical with the divine person of the Logos, his human actions in fulfillment of the law were infused divine power and glory. By this human obedience, he did what only God could do and renewed creation. In order to accomplish this, Christ took over and fulfilled the offices of Adam, the protological prophet, priest, and king."