Within the ancient world kinship and family were a person's primary source for status. The reputation of one's ancestral house was an important factor in how one viewed one's self, and how others viewed you. Kinship was a root of self-identity and understanding.
The Jews had a special focus on this, as for example those descended from Levi and Aaron were determined to be the ones suitable for Temple ministry. The book of Esdras notes that those among returnees from Babylon who could not prove Levite lineage were not permitted to perform Temple service.
In this context the genealogies of Jesus were called upon to serve certain purposes. Let's note some relevant points:
- A Skeptic states that we need to "explain why the Luke genealogy contains almost twice as many ancestors as Matthew's in the same time period."
Miller rightly answers that this is an example of a "simple pedagogical/rhetorical technique of Matthew (common in his day)". In more detail, in a predominantly an oral culture, things had to be memorized, and memory was made easiest by making things as short as possible while still retaining their purpose. Matthew's intentional breaking of Jesus' lineage into 3 blocks of 14 is indeed a memory device. Such fluidity in genealogical records is not exclusive of the Bible.
"By virtue of its form a linear genealogy can have only one function: it can be used to link the person or group using the genealogy with an earlier ancestor or group. The actual number of names in the genealogy and the order of those names play no role in this function, and for this reason names are frequently lost from linear genealogies, and the order of the names will sometimes change." [I Studied Inscriptions from Before the Flood, 213]
The removal of names and the telescoping of lists is known in other oral cultures -- and it is also known that certain numerical patterns were preferred.
- "In any given society, genealogies may function in more than one of the three spheres...it would be possible for a society to have a number of apparently conflicting genealogies, each of which could be considered accurate in terms of its function." [I Studied Inscriptions from Before the Flood, 213] So why are Jesus' genealogies different?
Luke's goes all the way back to Adam and has 56 generations. His interest is in establishing a tone of universality in the Gospel message and mission, as he does in Acts with the admission of Gentiles into the Kingdom of God. This is all there is to his purpose, and so the genealogy is linear rather than segmented.
Matthew's goes back to Abraham and has 3 groups of 14 generations. Here he certainly telescopes, as noted above (and Luke probably does, too). But Matthew is trying to prove certain points with his genealogy that Luke is not. He is, first, trying to establish Jesus as a legitimate heir to David's throne, and thus he uses the lineage through known names in 1 and 2 Kings.
Second, Matthew has split into blocks of 14 so as to match the Hebrew sum for the numerical equivalent to the name David (14), and to match the breaks with significant events in Jewish history, the "pedagogical device" Miller refers to.
Finally, Matthew wants to include some women of a questionable character, because they serve as an "in your face" to the expected charge that Jesus' own birth was in some way scandalous or abnormal. Neyrey in Render to God  argues that a critical purpose of Matthew is to employ a sterotype of "covenants of promise," hence the exclusion of Moses and any priestly members, and the inclusion of persons like the women (and Jeconiah) that show that "God's blessings worked through these disqualifications [these persons had] because God is free to choose whom God chooses."
- Finally, a note for those who make much of Mark providing no genealogy: He does. It is any place where he identifies Jesus as the "Son of God" thus giving Jesus more status than he would ever achieve through Mary or Joseph.
One would expect of course that critics find in these purposes evidence of malfeasance or fiction in Jesus' genealogies, but that is merely a case of assuming what has yet to be proven. As Miller has shown, there are viable ways of understanding how both genealogies would be accurate.
This commentary is intended as a supplement to Glenn Miller's excellent work on the genealogies of Jesus and is intended to draw out a few extra points of relevance about the use of genealogies in the ancient world. For more detail on this subject see out item here. Our primary source for this commentary is deSilva's Honor, Patronage, Kinship and Purity [158ff].