Matthew knows the importance of tracing Jesus' ancestry to King David to support his argument. The royal Messiah must necessarily descend from Judah and David. Indeed, Herod the Great, who ruled at the time and called himself king, could not, in Jewish eyes, officially claim this title, because he did not belong to that royal line.
The ‘King of the Jews’ can only be a descendant of Judah and David. Matthew's list gives Joseph's ancestry. The argument is clear: under Jewish law at that time, Jesus the Messiah inherited this royal lineage through his adoptive father, Joseph, and could therefore claim the title of King of the Jews.
We will also discuss the five women mentioned in this list, something highly unusual.
Luke specifies Jesus the Messiah's age at his baptism. His use of ‘about’ does not allow us to assume a range of several years. On the contrary, we believe Luke was precise, as usual, and checked this information.
We therefore use this information to calculate Jesus the Messiah's birth date. As mentioned earlier, we have a different genealogy here, Mary's, whereas Matthew presents Joseph's. We explain this choice in Appendix 10: ‘The two genealogies of Jesus the Messiah’.
Luke took account of how difficult this adoptive lineage might be for a non-Jew to understand, since it could be perceived as deceptive.
What use is the genealogy of someone who played no role in the child's birth?
His research enables him to establish that Mary also belongs to a royal line. A maternal genealogy is usually rejected by Jews, but Luke addresses a Gentile audience. This maternal lineage, though surprising, follows from the very nature of Jesus the Messiah's unique birth.
Jesus the Messiah's humanity, transmitted through Mary, is attested by Luke, while his kingship is confirmed by Matthew. Luke also recognises Jesus' kingship, although this is not his main purpose. Luke declares that Jesus the Messiah is the Son of God, a claim difficult for Jews to accept, but he is addressing converts from paganism.