A Statement of the Manner in Which Luke's Procedure is Proved to Be in Harmony with Matthew's in Those Matters Concerning the Conception and the Infancy or Boyhood of Christ, Which are Omitted by the One and Recorded by the Other
14 After the enumeration of the generations, Matthew proceeds thus: Now the birth of Christ was on this wise. Whereas His mother Mary was espoused to Joseph, before they came together, she was found with child of the Holy Ghost. What Matthew has omitted to state here regarding the way in which that came to pass, has been set forth by Luke after his account of the conception of John. His narrative is to the following effect: And in the sixth month the angel Gabriel was sent from God unto a city of Galilee named Nazareth, to a virgin espoused to a man whose name was Joseph, of the house of David: and the virgin's name was Mary. And the angel came in unto her, and said, Hail, you that are full of grace, the Lord is with you: blessed are you among women. And when she saw these things, she was troubled at his saying, and cast in her mind what manner of salutation this should be. And the angel said unto her: Fear not, Mary; for you have found favour with God. Behold, you shall conceive in your womb, and bring forth a son, and shall call His name Jesus. He shall be great, and shall be called the Son of the Highest; and the Lord God shall give unto Him the throne of His father David: and He shall reign in the house of Jacob for ever; and of His kingdom there shall be no end. Then said Mary unto the angel, How shall this be, seeing I know not a man? And the angel answered and said unto her, The Holy Ghost shall come upon you, and the power of the Highest shall overshadow you: therefore also that holy thing which shall be born shall be called the Son of God; and then follow matters not belonging to the question at present in hand. Now all this Matthew has recorded [summarily], when he tells us of Mary that “she was found with child of the Holy Ghost.” Neither is there any contradiction between the two evangelists, in so far as Luke has set forth in detail what Matthew has omitted to notice; for both bear witness that Mary conceived by the Holy Ghost. And in the same way there is no want of concord between them, when Matthew, in his turn, connects with the narrative something which Luke leaves out. For Matthew proceeds to give us the following statement: Then Joseph, her husband, being a just man, and not willing to make her a public example, was minded to put her away privily. But while he thought on these things, behold, the angel of the Lord appeared unto him in a dream, saying, Joseph, you son of David, fear not to take unto you Mary your wife, for that which is conceived in her is of the Holy Ghost. And she shall bring forth a son, and you shall call His name Jesus; for He shall save His people from their sins. Now all this was done that it might be fulfilled which was spoken of the Lord by the prophet, saying, Behold, a virgin shall be with child, and shall bring forth a son; and His name shall be called Emmanuel, which, being interpreted, is, God with us. Then Joseph, being raised from sleep, did as the angel of the Lord had bidden him, and took unto him his wife; and knew her not till she had brought forth her first-born son; and he called His name Jesus. Now when Jesus was born in Bethlehem of Judæa, in the days of Herod the king, and so forth.
15. With respect to the city of Bethlehem, Matthew and Luke are at one. But Luke explains in what way and for what reason Joseph and Mary came to it; whereas Matthew gives no such explanation. On the other hand, while Luke is silent on the subject of the journey of the magi from the east, Matthew furnishes an account of it. That narrative he constructs as follows, in immediate connection with what he has already offered: Behold, there came wise men from the east to Jerusalem, saying, Where is He that is born King of the Jews? For we have seen His star in the east, and have come to worship Him. Now, when Herod the king had heard these things, he was troubled. And in this manner the account goes on, down to the passage where of these magi it is written that, “being warned of God in a dream that they should not return to Herod, they departed into their own country another way.” This entire section is omitted by Luke, just as Matthew fails to mention some other circumstances which are mentioned by Luke: as, for example, that the Lord was laid in a manger; and that an angel announced His birth to the shepherds; and that there was with the angel a multitude of the heavenly host praising God; and that the shepherds came and saw that that was true which the angel had announced to them; and that on the day of His circumcision He received His name; as also the incidents reported by the same Luke to have occurred after the days of the purification of Mary were fulfilled—namely, their taking Him to Jerusalem, and the words spoken in the temple by Simeon or Anna concerning Him, when, filled with the Holy Ghost, they recognized Him. Of all these things Matthew says nothing.
Source: The Harmony of the Gospels (New Advent)