What does Luke 2:9 mean?

The men visited here are shepherds in the middle of an otherwise ordinary night guarding sheep (Luke 2:8). Nearby, Mary has just given birth to the Messiah, Jesus (Luke 2:6–7). Why the angel delivers this message, the Bible does not explicitly say. The fact that Jesus' arrival is meant as good news for all mankind, even the poor and lowly, might be highlighted by God's choice to make common shepherds the first on earth to learn what has happened.

Scripture indicates that people who see angels in "spiritual" form often respond with fear (Luke 1:13; Matthew 28:4; Numbers 22:3). That's not surprising when one considers how powerful these beings are (Genesis 19:12–13; 2 Kings 19:35). Even if someone recognized the being as a messenger of God, they would probably remember that angels do not always come with good news (2 Samuel 24:16). The appearance of this angel must be especially dramatic. The men are described using the Greek phrase ephobēthēsan phobon megan, literally meaning "frightened with massive fear." They aren't merely unnerved or startled: they are struck with terror.

Thankfully, the angel will quickly reassure them and go on to explain the reason for his visit (Luke 2:10–11). The initial fright will turn into wonder (Luke 2:13–14), then excitement (Luke 2:15–16), then triumph (Luke 2:20).