In a real sense, Jesus has three genealogical lines. Each of these lines has significance as to His person. We will look at each of them in turn.
Jesus was born of the virgin Mary by the Holy Ghost. Therefore, in the announcement of the angel to Mary about the birth (Luke 1:31-35), Jesus is called "the Son of the Highest" (v.32) and "the Son of God" (v.35). Even at age 12 when He spoke with the doctors in the temple, Jesus knew that God was His "Father" (Luke 2:49). In explanation of His special relationship to God as Father, Jesus testified, "I proceeded forth and came from God" (John 8:42). First and foremost, this is the genealogy of Jesus.
SUPPOSED EARTHLY FATHER
However, in addition to His heavenly Father, Jesus had one who served as his earthly father. Joseph was not the biological father of Jesus and the scriptures make this very clear. Concerning Jesus, Luke 3:23 states, "being (as was supposed) the son of Joseph." In two different verses (Luke 2:33, 43), the text of scripture refers to the earthly parents of Jesus as "Joseph and his mother." This clearly denies the physical parentage of Joseph.
However, others looked on Joseph as the father of Jesus. The multitudes consider Christ to be "Jesus, the son of Joseph, whose father and mother we know" (John 6:42). They looked on Him as "Joseph's son" (Luke 4:22). And, since Jesus was to sit on the throne of His father David, His genealogy through His supposed earthly father would be important. If He is to be king of all Israel, He must have a male genealogy back to David. This is the genealogy we find in Matthew, chapter one.
Mathew, of the four gospels, is the gospel that deals most with Jesus as the King of the Jews. It is in Matthew that the wise men of the east seek Him that is born King of the Jews (Matthew 2:1-2). The genealogy of Matthew begins by introducing Jesus Christ as "the son of David" (Matthew 1:1). In the eyes of the Jews, in order to be king He would have to be able to trace his royal line through his father. That is why the genealogy of Joseph is given in Matthew. But even here, great care is taken to show that Joseph was not the biological father of Jesus. The genealogy ends with, "And Jacob begat Joseph the husband of Mary, of whom was born Jesus, who is called Christ" (Matthew 1:16). Jacob begat Joseph--that is biological. But Joseph was simply the husband of Mary of whom was born Jesus. The remainder of Matthew, chapter one, tells of the virgin birth of Jesus.
So, the genealogy of Matthew is the genealogy of Joseph. It is given to establish the legal right of Jesus to the throne of David. However, if we want to understand the true human genealogy of Jesus, we must look at it through His mother Mary. That is the genealogy of Luke, chapter three.
The genealogy of Luke is radically different from the one in Matthew. Mathew goes from Mary's husband Joseph all the way back to David but Luke has different names between Joseph and David. Only before David do the two genealogies merge again and have the same names. However, although the genealogy of Matthew begins with Abraham, the genealogy of Luke goes all the way back to "Adam, which was the son of God" (Luke 3:38). This can be understand in light of the emphasis Luke makes concerning Jesus. Whereas in Matthew, Jesus is presented as the King of the Jews, in Luke He is presented as the Son of man. That is, the emphasis is on His humanity. So, although the King of the Jews need only trace his lineage back to Abraham to prove his Judaism, the Son of man needs to trace his lineage all the back to the first man- Adam.
The gospel that emphasizes the humanity of Christ is also the proper one to trace His biological genealogy through His mother Mary. Although a mother's genealogy did not usually matter greatly, Jesus had only one human parent and His biological genealogy had to be traced through that one parent. However, even here, Joseph stands in for Mary. The genealogy begins, "And Jesus himself began to be about thirty years of age, being (as was supposed) the son of Joseph, which was the son of Heli" (Luke 3:23).
Obviously, the passage does not say that it is the genealogy of Mary. However, we can rest assured that it is that of Mary for several reasons. First, it is completely different from the one in Matthew. This suggests that each genealogy follows a different parent. Second, giving both genealogies (although unusual) is required because of the unusual circumstances. Third, the Matthew genealogy uses the word "begat" to define the line. This is a biological term and pretty much has to refer to biological descent. The key phrase in Luke is "the son of." Although this often refers to biological descent, it is often used of adopted children and other situations as well. In a sense, Joseph adopted Jesus as His earthly son. The best understanding of the two genealogies is that Matthew refers to the line of Joseph for legal reasons and Luke refers to the human line through Mary.
However, there is another extremely important reason for the two genealogies. One of the kings of Judah in Matthew's genealogy is a man named Jechonias (Matthew 1:11-12). He was king during the time of the Babylonian captivity. Jeremiah also lived during this time and made an important prophecy concerning Jechonias (also called Jehoiakim and Coniah). Consider these prophecies concerning Jechonias.
Jeremiah 22:28-30 Is this man Coniah a despised broken idol? is he a vessel wherein is no pleasure? wherefore are they cast out, he and his seed, and are cast into a land which they know not? O earth, earth, earth, hear the word of the LORD. Thus saith the LORD, Write ye this man childless, a man that shall not prosper in his days: for no man of his seed shall prosper, sitting upon the throne of David, and ruling any more in Judah.
Jeremiah 36:30 Therefore thus saith the LORD of Jehoiakim king of Judah; He shall have none to sit upon the throne of David: and his dead body shall be cast out in the day to the heat, and in the night to the frost. According to the prophecy of Jeremiah, Coniah (Jehoiakim) will have no man of his seed to sit upon the throne of David. The word seed would refer to all of his future descendants. This was true during his time because of the Babylonian captivity. It has been true historically since that time. However, of Jesus it is prophesied that He shall be given "the throne of his father David" (Luke 1:32). That is a problem because the genealogy in Matthew includes Jechonias, a king God prophesied would never have a man of his seed sit on the throne of David. What is the answer? It is found in the second genealogy.
As you recall, the genealogy of Matthew is that of Joseph. It is the legal line of David that includes the kings of Judah. However, it is not the biological line of Jesus. That is found in Luke. This is where the genealogy of Luke becomes so interesting. It is not traced through Solomon the son of David (as the Matthew genealogy). Rather, it is traced through another son of David, a man named Nathan (Luke 3:31). Nathan was a younger brother of Solomon, being born to David and Bathsheba. So, although the Luke genealogy is traced through David, it avoids the cursed line of Jechonias. Jesus was of the legal line of David through His mother's husband, Joseph. However, He was not of the seed of Coniah (Jechonias). He was not biologically of the cursed line.
What a declaration of God's providential wisdom. Only He could have worked all of this out. Praise the Lord for His goodness! He took care of every requirement and gave His Son to be born to this earth so that He could fulfill the promise of the Jewish Messiah and offer Himself as the Saviour of the world. Thanks be to God for His amazing grace.