The apostle Matthew begins his telling of Jesus’ life with a genealogy. This is meant to show that Jesus is directly descended from both Abraham and King David, making Him a legal heir to the throne of Israel. He then tells the story of Jesus’ birth from the perspective of Joseph, Mary’s husband.

“The birth of Jesus Christ came about this way: When his mother Mary was espoused to Joseph, before they came together, she was found with child by the Holy Spirit.

Matthew 1:18-23 KJV
Now the birth of Jesus Christ was on this wise: When as his mother Mary was espoused to Joseph, before they came together, she was found with child of the Holy Ghost. Then Joseph her husband, being a just man, and not willing to make her a public example, was minded putting her away privily. But while he thought on these things, behold, the angel of the Lord appeared unto him in a dream, saying, Joseph, thou son of David, fear not to take unto thee, Mary thy wife: for that which is conceived in her is of the Holy Ghost. And she shall bring forth a son, and thou shalt 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 they shall call his name Emmanuel, which being interpreted is, God with us.