And 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 fear. And the angel said to them, “Fear not, for behold, I bring you good news of a 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. (Luke 2:8-18)
The first missionaries about the Messiah were not the apostles, and missions didn't start at Pentecost. Instead, God chose a simple group of people to carry His message that was heralded by angels.
God could have had the angels proclaim the birth of Christ throughout the world. He could have let everyone see the glorious light and the shining star. Yet He chose to reveal truth to a few, who would spread the word to so many more.
The shepherds were no different than you and I, really. Simply people who were recipients of revelation - and they passed that revelation on to others.
"And all who heard it wondered".
Continue to pass along to others what has been revealed to you!!!!