Matthew’s story of Mary’s pregnancy lacks the charm and detail of Luke’s account, but that may well be its value. One of the great enemies of the gospel is sentimentality, and the stories surrounding Jesus’s birth have proven to be ready material for maudlin sentiment. Matthew’s account of Jesus’s conception and birth is unapologetically realistic.
Joseph, not Mary, is the main actor. John Chrysostom praises Joseph as a man of exceptional self-restraint since he must have been free of that most tyrannical passion, jealousy. Unwilling to cause Mary distress, to expose her to public disgrace, he planned to dismiss her discreetly. Joseph, therefore, refused to act according to the law, but rather chose to act in a manner that Jesus himself would later exemplify by his attitude toward known sinners (Matt. 9:10–13).
Yet Joseph still required a revelation so that he would know the character of Mary’s pregnancy. He is also given the honor to name Jesus as the new Joshua capable of rescuing his people from their sins. The Joshua of old had been given the task of conquering the promised land, but this Joshua is sent to save his people from their sins, making it possible for them to live as the people of the promise. Joseph did as he was instructed, taking Mary for his wife and naming his son Jesus.
Moreover, Matthew tells us all this was done so that the prophecy of Isa. 7:14 would be fulfilled. This is the first time that Matthew uses the formula “all this took place to fulfill what had been spoken by the Lord,” but he will use the formula often to show how Jesus fulfilled the prophecies of the Old Testament.