The Self-Donation of God, chapter 13:
"Finally, we turn to Christ's prophetic office (munus propheticum). As we have seen earlier, Adam as the protological minister of the Word, failed to trust in and properly apply the Word of God when faced with the challenge of Satan. By this, sin and death entered into the world (Rom 5:12). Jesus Christ reverses Adam's falsehood and introduction of death because he is "the faithful witness, the firstborn of the dead . . ." (Rev 1:4). The exercise of all Christ’s offices is ultimately ordered to his prophetic office. By actualizing a new testament in his blood, he establishes the Word of the gospel which destroys sin, death, the law, and the Devil.
Because Jesus is the eternal Word of God and the true prophet, all divine revelation centers on him. According to Deuteronomy 18, truth of prophecy is predicated on whether the prophet speaks in the name of YHWH and whether that prophecy comes true. As the "yes" to all of God's promises (2 Cor 1:19-20) and as the true divine Name, Jesus Christ supremely embodies this criterion. By his Incarnation, all of God's promises spoken by him in his pre-incarnate state through the prophets came true. He is both the source and object of revelation. Similarly, he does not just speak in the divine Name, but is the divine Name in person. Within Jesus' ministry, his own prophecy and that of all those who testify to him was validated by the supreme fulfillment of the resurrection.
In his resurrection, Jesus confirmed his testament which he gave to the Church through apostolic word. As we have seen in our discussion of the book of Revelation, the opening of Christ’s testament unleashes the power of the new creation which undoes the dominion of the Devil. God's war for creation is a war between the word of Christ's testament and Satan's false word (John 8:44). As we saw earlier in texts such as the Genesis commentary and the Smalcald Articles, Luther understood this fact and juxtaposed faithfulness and truth of God's Word with Satan's corruption of the Word. Indeed, as John teaches the ultimate goal of Christ’s work is to undo the falsehood of the Devil: “The reason the Son of God appeared was to destroy the Devil’s work” (1 John 3:8)."