Why are the genealogies of Jesus in Matthew and Luke different?
The major genealogies of the Old Testament avoid any suggestion that they shift in such a way as to make a cousin or uncle or member of another family into the father of someone in that genealogy. The genealogies always move from father to son (or in reverse in the case of Luke 3). Why then do there appear to be two different genealogies of Jesus in Matthew 1 and Luke 3, each containing different sets of names? It is possible that one of these could be the line of Mary. If so, it would be thought that the one that lists the kings of Judah (Matthew 1:1-17) would be Joseph’s line (through which descent was reckoned) and the Lukan genealogy of 3:23-38 would be that of Mary. While this is theoretically possible, it seems less likely in light of Luke 3:23 where the line most clearly moves from Joseph, not Mary. The same is true in Matthew 1:16.
Because Matthew 1 includes the kings of Judah while Luke 3 presents a list of other names at this point, many feel that Matthew’s genealogy is a royal one reminding the reader that the line included the royal figures of Judah, as expected in the Messiah. However, the line of Luke may provide the biological line explaining that Jesus’ line was indeed through these figures. If this is the case, then David’s son in Luke (3:31) is an otherwise unattested Nathan. And Jeconiah (Matt. 1:11) was not the physical father of Shealtiel, but the last living king of Judah before the end of the line of kings in Jerusalem. Neri (Luke 3:27) was the biological father of Shealtiel. From there to Jesus the two gospels each has a selective (not comprehensive) group of names. Nevertheless, both begin and end together, so both have a claim to trace the ancestry of Jesus. And, while neither wanders off into a brother or cousin or a different family, the emphasis on each of the gospel writers determines who is presented.
A clue to the royal representative line of Matthew may lie both in its careful structuring around the key figures of Abraham, David, and the Exile (1:17) and the unique introduction in 1:1. There Jesus is identified as “the Messiah, the son of David, the son of Abraham.” This opens the door to understand what follows as less of a biological line ( as is the case with Luke) and more of a symbolic line of royal figures in the middle 14 generations. David heads that line and is indeed the biological ancestor of Jesus according to both Matthew and Luke. The succeeding kings demonstrate that David’s successors were a royal line.
