Why does Mary sing?

She rejoices for good reason, as did Hannah, the mother of Samuel, when she received a child (1 Samuel 2). Both ­women sing of God's mercy for the humble. They rejoice that God is not impressed by pride, riches, or power. They shout with joy that God keeps his promises; he makes mercy the currency of his kingdom—always.

Luke includes songs to sum up the events in which people take part in the story of Christ's birth. He includes songs by elderly men like Zechariah (1:67-79) and Simeon (2:29-32). There's also a song-summary of the angels' message at Christ's birth (2:14).

If your Bible has cross-references, you will notice that Mary's words in her song are adapted from other songs, mostly Hannah's prayer and the Psalms. This makes Mary a clever arranger. Or, better, it shows that Mary's song echoes the timeless voice of believers everywhere who hang on to God, believing in his great ­power to save and to rule in righteousness and mercy. They may not be on Time magazine's list of 100 influential people, and the world may not notice their need or poverty, but God pays attention. And God acts!

We remember at Christmas that God's mercy is at work in our world, and that it may be hidden—like the baby in Bethlehem.