The incarnation of Christ was indeed the most wonderful of God’s wondrous works. But it was the most unsurprising surprise. God’s hand had guided the story of redemption to this culmination. Like a lovely symphony the OT introduces certain motifs, which are picked up and expanded in the Incarnation of Christ. So, it would be wise for us to listen to those themes from the OT that anticipated the events surrounding Christ’s birth in order to better sing the Gospel song.
