We have shown that the happy birth of Christ freaked out lots of people. After saying “fear not” to Zacharias, Mary and Joseph, there’s one more recipient of this message–the shepherds.
The shepherds have a good reason to be afraid–the glory of the Lord shone all around them. That would be scary, God’s got lots of glory to shine. God’s glory can be a good thing or a bad thing, depending on who you are. The angels tell the shepherds that they’ll be OK, this is good news.
God’s glory can fry you if you’re a sinner. But if you’re one of His, you’re fine in His glory, in fact, you can bask in it. The shepherds respond perfectly–”let’s go to Bethlehem and check this out!” They got a taste of God’s glory and wanted to see the rest.
The Good News of Christ’s birth is that sinners can now be saved. God’s glory won’t fry us anymore, now it brings peace. It brings salvation. Fear not!