Lots of people have noted that we have two different genealogies in Matthew and Luke’s gospels. There are a few different explanations for how Jesus can have two different yet legitimate family trees. I am not going to spend any time on that today, you can do your own research to see the various explanations. Here, I want to look at the reason why Matthew and Luke are keen to offer different genealogies – what is each of them trying to achieve?
Matthew’s emphasis is very much on Jesus’ kingship. He is most interested in showing that Jesus is the Messiah that the Jews have been waiting for. Luke, by contrast, focuses more on Jesus’ humanity. He is writing an orderly historical biography of who Jesus was supposed to be. These two different purposes explain something of the reason behind the differing genealogies.
Matthew takes his gospel through three stylised groups. He begins with Abraham (with whom God made a covenant), follows Jesus’ lineage through David (with whom God made a covenant) and then traces the line through the post-exilic period (showing that the respective covenants are still in force). Matthew’s purpose is relative clear. He is tracing the royal line of the Messiah. A line that must run from Abraham, through David and remain in tact after the exile. Such a line can be traced all the way to Jesus, the one Matthew highlights as the Messiah.
Luke, by contrast, is more interested in showing that Jesus is, indeed, a real man. He traces Jesus’ biological line all the way back to Adam. He even alludes to this purpose when he emphases in 3:23: ‘Jesus was about thirty years old and was thought to be the son of Joseph…’ Luke wants to show that Jesus was thought to be the son of Joseph and shows how his presumed biological line goes all the way back to Adam.
Both Matthew and Luke have different purposes in their gospels. One wishes to show the royal linage of Jesus that qualifies him to be the Messiah. The other wants to show the presumed biological line of Jesus. Both writers wish to highlight different aspects of the man Christ Jesus so that his claim to be the Messiah and his fitness as a mediator between God and man is made clear.