When Jesus was 12 years old he decided to stay in Jerusalem to join the rabbis in the temple and train to become a rabbi. He made an impressive start, but then his mum turned up. She insisted that he return home to Nazareth and train, instead, to be a builder - like Joseph. That one story tells us a lot about why God chose Mary to be Jesus’ mother. In choosing Mary, God chose ordinariness. The Son of God did not come to be special; he came to be ordinary.
This ordinariness can also be seen in the Biblical accounts of Jesus’ birth. Forget the stable, the kindly landlord, Mary's melodramatic ride on a donkey while in labour, and the remarkably bright and moving star. These are mythical additions from centuries of european tradition. What the Bible actually tells us is that Jesus was born in Joseph’s family home, where Joseph and Mary had decided to settle and stay. The only catch was that the guest room was already taken, leaving Mary and Jesus in the cellar where the sheep were kept during the winter.
Jesus’ actual birth was so unremarkably ordinary that two of the Gospels don’t mention it at all, and Matthew only makes a passing reference.
In this ordinariness we see the choice of God. Ordinariness is good!