9. Whoever, therefore, desires to overcome and be safe from the devil's poison and evil must rivet his attention on these wonderfully comforting words of the angel, "unto you is born a Saviour." When this conviction reigns in our heart the victory is already won. We can now counter: Though the devil throttle me, deeply imbed sin in me, and inject me with his poison to bring me under God's wrath and everlasting judgment, yet I will not be overcome with fear and terror to the point of despairing. For great though this evil is, it cannot in any way be compared with the treasure God has given us through Christ. It is far greater than the evil the devil has brought about in us. We don't understand why God did not take charge over the human race in the same way the devil has dominion over people, but instead chose to become a true man himself. That near the devil cannot come to people, to become a human being, man remains man, and the devil remains the devil, two distinct persons and natures. The Son of God, on the other hand, assumed a human nature, so that I can now say in truth: This man is , and is called, true God; and conversely God is, and is called, true man in one person.
10. God thus has drawn much closer to us and entered more deeply into our condemned and troubled nature than the devil could. He can possess and torture a person but cannot personally become a human being, as, conversely, a human being cannot become a devil. The two natures remain distinct not only in essence but in person. But with the Son of God the two are one; he has our flesh and blood, born of the virgin Mary, true, natural man like you and me, except that he was conceived by the Holy Ghost without male semen, and did not partake of the devil's poison, sin and death, but possessed a completely pure, guiltless body and blood. Except for that one fact, that our body and blood are impure and sinful, he is a man like you and me, needing to eat, drink, sleep, wake up, become tired, rest, and carry on as other people need to do because of their nature. As St. Paul says, habitu inventus ut homo, "in his appearance he was found in fashion as a man," so that whoever saw or heard him would have to say, he is a true human being in nature, no apparition, for he possesses all the characteristics of human life.
11. This was the gladness of which the angel spoke. I speak now only of the glory over which we should rejoice, not yet about the fruit of his suffering and resurrection. My sermon now is only about the glory with which God honored our nature, that against all dishonor and shame brought upon us by the devil through sin, we came to blessedness in that God drew so near to us by himself becoming a man in his own person like you and me, except that he was without sin. Thereby he adorned the whole human race with this inexpressible honor. This is what the angel wanted the people to perceive with his words, "I bring you good tidings of great joy, which shall be to all people."
12. The dear angels rejoice because of the birth of this Saviour, and they glow and spring happily, completely at peace with mankind. That is the essence of the angel's joyous sermon, "I bring you glad tidings which shall be to all people." His deep desire is that none of us in the human race be excluded from this rejoicing but that all would espouse these glad tidings from the heart, as the angels did, that by Christ the Lord's birth our human nature has been greatly elevated, because the most sovereign Son of God himself, by whom all things were made, has become flesh and blood with us.
13. If there was nothing more for us in the newborn child than that our human nature had been highly honored in that God who created us is now our kinsman, our nearest friend, our flesh and blood, (I'll omit for the present to speak of his suffering and resurrection), it would be little wonder, if we, believing it from the heart, would become so dear to each other that, as the saying goes, we would consume each other with love. If our hearts really perceived the greatness of this honor and we could say with firm faith, God is become man, would it be a wonder if we no longer were enemies with any man and surrendered our lives for each other? The fact is you could not even hate or harm anyone in effigy who has body and soul like your God and mine. Should we not, therefore, because of such glory with which God has elevated human nature above and beyond the angels, also love and do good to all people?
14. The angels are much more glorious creatures by nature than we human beings. But God did not consider that; he is not an angel, nor did he become an angel. The angels, moreover, are blameless and holy spirits who have never fallen, as the other angels and we poor humans did, and therefore they are also immortal. That seems to suggest that it would have cost the divine nature less, if God had become an angel. But he sets the course, chooses the lowly, poor human nature, lost in sin and subject under the devil's rule and the power of death, plagued and troubled through and through by the devil and his ceaseless pressure. That meant sinking to the lowest depths. That fact alone ought to motivate us to ardor, love, kindness, ands service toward each other for the sake of this one man, Jesus Christ.
15. Some of the fathers, in particular Bernard, in reflecting on the matter have stated that when the devil, while still in heaven, saw that the Son of God would become man, he became so filled with envy against people and hatred toward God for not becoming an angel rather than man, that out of jealousy and arrogance he fell to his ruin. That may be a pious thought or an actual fact, but in any case the beloved fathers sought thereby to emphasize the great joy, glory, and overwhelming goodness that have come to us, because God took to himself not the angel's nature, but through Abraham's seed our flesh and blood, which had been corrupted by the devil and poisoned through sin and death.
16. People who know nothing of this glory are without hope of salvation, but much worse are those who hear the message of the angels or from the apostles-that God graciously embraces our human nature, honors and magnifies it so highly, that not even the angelic nature equals it in comparison, in fact no creature made by God. But they do not savor it, nor do they have comfort or joy from it. You may be sure they forfeit their salvation. They neither fathom nor possess it.
17. If my father were to become a great and wealthy lord, I would indeed be very happy. When one member of a large family of brothers is promoted they all share in the joy and satisfaction. How great was Israel's joy when Joseph was elevated to prince in Egypt. it is a natural gladness. So how does it happen that we do not rejoice over this inexpressible honor and glory? Why doesn't it grab us in our hearts? and why don't we praise and thank God over the fact that he assumed our flesh and blood and now sits at the right hand of God, Lord over all creation?
Klug, Eugene F. A. Sermons of Martin Luther: The House Postils Vol 1. Grand Rapids: Baker Books, 1996.