Matthew’s main prospective centers around the premise that Jesus was the Messiah of the prophecies of the Tenakh or as Christians call it Old Testament. Many of the points that Matthew makes, point out how Jesus fulfilled specifically the Messianic prophecies.The Greek word Christ is Messiah in Hebrew.
In Matthew chapter one, Matthew pointed out Jesus’ genealogy and how it relates to his right to the throne of David. Prophecies said that the Messiah would be of the Son of Abraham,(Matthew 1:1, Genesis 12:1), that he would be called the Son of David, (Matthew 1:1, Isaiah 11:1-2). That he would come through the royal line of Solomon because God promised David that Solomon would sit on the forever (2 Samuel 7). It is important to note here that this lineage is through Joseph, the adopted father of Jesus. Because God had cursed Jechoniah of the royal line and swore that no seed of his should ever sit on David’s throne, the only way this could be fulfilled was that Jesus, the Son of David through Nathan (another son of David) and Mary to become the legal heir to David’s throne through Joseph of the kingly line shown here in Matthew. The lineage of Mary is shone in Luke chapter 3:23-38 which goes back to Adam.
Matthew 1:18-20 explicitly points out that Jesus was not Joseph’s biological son. Mary, who was still a virgin was impregnated supernaturally by the Holy Spirit. Joseph knew that he didn’t have sex with Mary and if she was pregnant, he knew that he wasn’t the father. Because he was a good man, he didn’t want to make a public example of Mary, but was planning a private divorce. (Betrothal before consummation was still considered an marriage contract in the Jewish culture of that time.) God (through the angel of the Lord) intervened by coming to Joseph in a dream and explained the situation.
The angel of the Lord explained to Joseph that Mary was pregnant with God’s son. That he was to name the child Jesus: for he would save his people (the Jews) from their sins. He said that this was the fulfillment of the prophecy of Isaiah 7:14.” Therefore the Lord himself shall give you a sign; behold, a virgin shall conceive and bear a son, and shall call his name Immanuel.” In Matthew they use the Greek translation Emmanuel meaning “God with us”. In other words, Jesus which means God is salvation is God living and dwelling with us.
Joseph listened to the Angel of the Lord. He accepted the responsibility of Mary as his wife. He did not have sexual relations with her until after Jesus was born. Jesus was the legal son of Joseph, even though he was not his biological son.