1) The poem describes the night of Jesus's birth, with the inns full and streets empty as Mary gives birth in a stable while Joseph paces outside.
2) Shepherds in the fields are visited by angels announcing Jesus's birth, and they and wise men come to see the newborn king laying in the manger.
3) The poem asks the reader to look upon the baby Jesus in the manger and see not just a child, but the price God paid by sending his son to live and die for humanity, taking our sins upon himself.