The Angels, from Lucifer's Fall onward, have known the full, revealed glory of the Lord. They eternally sing of God's thrice holiness--Sanctus! Sanctus! Sanctus!--and power as Lord of hosts. The angels were there when God laid the foundation of creation and set its corner stone; they heard the first morning stars sing, and shouted with joy at the sight (Job 38:4&7). From the lofty heights of heaven, they watch all of God's plan in creation unfold before them. They have carried God's wrath to earth and bore Torah to the people of Israel. The Seraphim burn brighter than a million stars with the proximate Love of the Godhead, and the Cherubim bear God's throne. Their knowledge was full and complete, and while I can't imagine that the angels existed in a state that could be called jaded, there was, perhaps, something of an air of confident knowledge that they had seen it all.
But when the angels saw the Incarnate Lord, here was something new ... the eternal Word, without beginning or end became flesh, became Man at a moment in time. When God created humanity, certainly the angels saw the image and likeness in which God made them; they knew God's living force empowering each movement of body and soul by the Spirit breathed into flesh. But never before had they seen God-man, not merely image or likeness but God as man, weak, almost powerless as he lay in the arms of his very human mother. God, who makes the clouds His chariot, who walks upon the wings of the wind, (Ps 104:3) who wields shafts of fire (Ps 7:13), now wrapped in swaddling clothes, unable to move at all. And I would like to think that God did not create angels without the capacity for surprise, and that at such a sight, they expressed surprise in joyous laughter (what else could you call "Alleluias" but sacred laughter?).
And this was not a trick of lights or prestidigitation. The Son was not merely clothed in flesh or the false image of a man: Jesus of Nazareth is fully God and fully Human. And so through His life, the angels saw God hunger and thirst, God shiver with cold and sweat in the heat, the muscles of God ache, and God know the peace of slumber after long day's work. They saw God suffer, chained, beaten and scourged, spat upon, and reviled. They saw God bleed. They saw God offer his life, the one life that humans get, upon the cross.
They saw God die.
I imagine that blew the angels away, and they were torn between the desire to cry and the desire to shout in triumph at the defeat of the Enemy and the tearing of the veil that separated Earth from Heaven. And yet the story wasn't over ...
They saw God on earth wrapped again, not in gentle swaddling clothes, but in a shroud to be entombed, buried in the earth. Again, I suspect the angels were once again in a state of unknowing, as they had never been, and I imagine an expectant hush fell over heaven in anticipation of what God would do next ... and then in the pregnant pause, the subtle whispered voice of the Spirit:
The absolute ruckus of ecstatic joy that then pealed through heaven and earth, I cannot imagine, though sometimes I think I catch the echoes of it when there's a particular surging of my heart in prayer.
With the Resurrection and Ascension, there is now, I think, an eternal state of expecation bound inextricably with endless surprise among the angels. The Son of Man has entered once for all into the eternal sanctuary (Heb 9:12) and there humanity has its great high priest (Heb 4:14) where we were to be eternally denied by sin. Every eye in heaven watches the resurrected and transfigured Christ Jesus make the eternal offering, not of the blood of goats or bulls, but the blood of the Slain and Risen God-man, the body of the Word-made-flesh. And that miraculous life of Jesus of Nazareth, that Passion, Death, and Resurrection, that eternal sacrifice, God gives to us again and again in the Mass. This thing, new and wondrous to angels, is present at every celebration of the Eucharist, a free gift and offer of thanksgiving and praise from the Father, by the Son and in the Holy Spirit.
How can we not, at the singing of the Sanctus, feel ourselves one with the angels who have known the glory of God? How can we not, at the invocation of the Holy Spirit upon the gifts, not wait with baited breath to hear the Spirit whisper, "Watch this?" And how can we not respond with raucous spiritual joy to know the presence of Our Lord in the signs of Bread and Wine, crying "Our Father! Abba!" the sign and proof that the gift of sacrifice has been received and in turn the Holy Spirit has been given to us? How can we not live lives of eternal expectation and limitless surprise when we ourselves receive the body and blood of Christ--knowing that we are in communion with He who stands in Heaven before his Father?
So now the angels look upon this humanity, once lost in the desert and now risen to heaven with the humanity of the Son. How each angel's eyes sees in each of us, glowing with the grace of the Eucharist, the potential of a new Christ, transfigured even now by God's grace! How they must look upon us and say, "Look how he makes all things new. We never knew; we never knew."