This evening he [Martin Luther] was very joyful. His conversation, his singing, and his thoughts were about the incarnation of Christ, our Savior. Amid his sighs he said, “Ah, what wretched people we are! To think that we are so cold and slothful in our attitude toward this great joy which, after all, happened for us, this great benefaction which is far, far superior to all other works of creation! And yet how hard it is for us to believe, though the good news was preached and sung for us by angels, who are heavenly theologians and have rejoiced in our behalf! Their song is the most glorious. It contains the whole Christian faith. For the gloria in excelsis is supreme worship. They wish us such worship and they bring it to us in Christ
“Ever since the fall of Adam the world knows neither God nor his creation. It lives altogether outside of the glory of God. Oh, what thoughts man might have had about the fact that God is in all creatures, and so might have reflected on the power and the wisdom of God in even the smallest flowers! Of a truth, who can imagine how God creates, out of the parched soil, such a variety of flowers, such pretty colors, such sweet vernal grass, beyond anything that a painter or apothecary could make! Yet God can bring out of the ground such colors as green, yellow, red, blue, brown. Adam and those around him would have been elevated by all this to the praise of God, and they would have made use of all created things with thanksgiving. Now we enjoy all this to overflowing, yet without understanding, like cattle or other beasts trampling the most beautiful blossoms and lilies underfoot.
“For this reason the angels here [in the Christmas story] recall fallen men to faith and love, that is, to glory toward God and peace on earth.” (Luther’s Works, v. 54, p.326)