Summary: Exploring the significance of angels announcing the birth of Messiah.
“In the same region there were shepherds out in the field, keeping watch over their flock by night. And an angel of the Lord appeared to them, and the glory of the Lord shone around them, and they were filled with great fear. And the angel said to them, ‘Fear not, for behold, I bring you good news of great joy that will be for all the people. For unto you is born this day in the city of David a Savior, who is Christ the Lord. And this will be a sign for you: you will find a baby wrapped in swaddling cloths and lying in a manger.’ And suddenly there was with the angel a multitude of the heavenly host praising God and saying,
‘Glory to God in the highest,
and on earth peace among those with whom he is pleased!’
“When the angels went away from them into heaven, the shepherds said to one another, ‘Let us go over to Bethlehem and see this thing that has happened, which the Lord has made known to us.’ And they went with haste and found Mary and Joseph, and the baby lying in a manger. And when they saw it, they made known the saying that had been told them concerning this child. And all who heard it wondered at what the shepherds told them. But Mary treasured up all these things, pondering them in her heart. And the shepherds returned, glorifying and praising God for all they had heard and seen, as it had been told them.” 
“Let us go over to Bethlehem and see this thing that has happened, which the Lord has made known to us.” Humble shepherds deserted their flocks and rushed to Bethlehem in order to verify what their senses told them could not have happened. Though the Son of God was born in humble circumstances, we must also know that He was heralded by Heaven’s choir. Have angels announced the birth of any other child other? Did ever such an august choir perform in more strange surroundings than did this choir?
With the bleating of sheep providing accompaniment, the messengers of heaven spoke to shepherds—the most humble representatives of mankind—to announce the birth of the Son of God. A field beyond Bethlehem became the site of the most famous announcement in all the history of mankind—the announcement that God would provide a redeemer for His fallen creature.
THE PLACE OF THE ANNOUNCEMENT — I phoned my dad, and then I phoned my grandmother. I phoned my brother and I phoned my mother-in-law. I even phoned my mother. I phoned my professors at school. I even phoned the local paper to place a birth announcement. I wanted everyone to know that Lynda and I had a baby girl to grace our home. The birth of one’s first child is momentous, and fathers especially want everyone to share their joy. The same note of infectious joy is noted in the account before us.
“There were shepherds out in the field.” Shepherds, in this particular area, lived in the fields throughout the period of March through November. There is nothing in this account to give us the particular timing of these events, but we are reasonably certain that they did not occur in late December. These particular shepherds were quite possibly caring for sheep destined for the Temple sacrifices.  Whether the sheep were their own, or whether they were indeed caring for sheep destined for the Temple offerings, it would be the responsibility of the shepherds to protect the flocks. Thus, they would remain in the fields with the sheep both day and night to protect the flock from robbers and from wild animals.
Some scholars have opined that these shepherds were the owners of the particular cave in which the child had been born, since they appear to have had no difficulty in finding the child after they were notified, but I think it fair to state that this is at best speculation. 
Why should this third announcement, the announcement of the birth of God’s Son, be to shepherds? Can we assign a particular significance to this announcement? Previously, there have been two other announcements in the brief account provided. The birth of John the Baptist was announced by Gabriel to his father, Zechariah [LUKE 1:5-25]; Gabriel also announced the birth of the Messiah to Mary [LUKE 1:26-38]. Now, we witness this third announcement, following the birth of the child. Whether it is Gabriel who makes this announcement or another of the heavenly messengers is not divulged by the text. What is related is that an angel of the Lord appeared to the shepherds.
Certainly, we can understand an angel announcing the birth of the Messiah to Mary. She would need to be prepared for the events which would follow. We don’t even struggle to account for the announcement of the birth of John to Zechariah. After all, God wished to prepare the old man and his wife for what was coming. However, why should God announce the birth of His Son to shepherds? Wouldn’t you think that God would wish the powerful to know of this event? Why should the announcement be to shepherds and not to those residing in Caesar’s palace? Why shouldn’t Herod be the first to hear of the birth of this child? The rich and powerful receive such deference in this world that we would imagine that they would be notified first of the birth of Messiah.