The people who walked in darkness have seen a great light

"Populus, qui ambulabat in tenebris, vidit lucem magnam – The people who walked in darkness have seen a great light" (Is 9:1).

(…) To the people, oppressed and suffering, who walked in darkness, there appeared "a great light". A truly "great" light indeed, because the light which radiates from the humility of the crib is the light of the new creation. If the first creation began with light (cf. Gen 1:3), how much more splendid and "great" is the light which inaugurates the new creation: it is God himself made man!

Christmas is an event of light, it is the feast of light: in the Child of Bethlehem the primordial light once more shines in humanity’s heaven and dissipates the clouds of sin. The radiance of God’s definitive triumph appears on the horizon of history in order to offer a new future of hope to a pilgrim people.

These joyful tidings (…) are also meant for us, the men and women of the dawn of the third millennium.

Long awaited, the splendour of the new Day at last shines forth. The Messiah is born, Emmanuel, God-with-us! He is born, who was announced by the Prophets of old and long invoked by all "who dwelt in the land of gloom". In the silence and the darkness of the night, the light becomes a word and message of hope.

But does this certainty of faith not seem to clash with the way things are today? If we listen to the relentless news headlines, these words of light and hope may seem like words from a dream. But that is precisely the challenge of faith, which makes this proclamation at once comforting and demanding. It make us feel that we are wrapped in the tender love of God, while at the same time it commits us to a practical love of God and of our neighbour.

https://www.vatican.va/content/john-paul-ii/en/homilies/2001/documents/hf_jp-ii_hom_20011224_messa-mezzanotte.html