Isaiah 7: 10-14
The prophecy in this reading from Isaiah speaks of the intervention of God in human history.  A child will be born, called Emmanuel, which means, “God is with us”.

Romans 1: 1-7
Salvation is offered through Christ Jesus, the Son of God, whose coming into the world is good news.

Matthew 1: 18-24
This is the fulfilment of the prophecy given in the first reading, telling the story of Mary conceiving a child through the Holy Spirit and giving birth to a son named Emmanuel.