The genealogies of the Lord Jesus recorded in Matthew 1:1-17 and Luke 3:23-38 differ widely. One way they differ is in grammatical structure: Matthew is straightforward and uses the indicative form of the Greek verb, GENNAW, (pronounced, as with the g in beginning, ge nah' oh) roughly forty times in his seventeen verse genealogy. GENNAW means to "beget, sire, become the father of." Luke, on the other hand, is more vague than Matthew, and Luke simply uses the genitive of relationship throughout, without telling his readers what that relationship is.

Furthermore, in the biblical view a man not only begets his children but his grandchildren, or great, great, great grandchildren, as well. We must remember Hebrews 7:9, 10: "One might even say that Levi, who collects the tenth, paid the tenth through Abraham, because when Melchizedek met Abraham, Levi was still in the body of his ancestor." Matthew gives us an abridged account of the ancestors of the Lord Jesus, clustered in three groups of fourteen: "Thus there were fourteen generations in all from Abraham to David, fourteen from David to the exile to Babylon, and fourteen from the exile to the Christ." (Matthew 1:17) Matthew, whose primary audience is the nation of Israel, traces the ancestry of Joseph through the line of the kings of Judah back to David, and then back to Abraham. He makes it very clear that Joseph is Jesus' legal father, not his biological father (1:18-25). Matthew demonstrates that Jesus is the legal heir to the throne of David.

Matthew's legal line has some sordid twists and turns, not only in the four women who are mentioned -- Tamar (who disguised herself as a prostitute to get her father-in-law, Judah, to fulfil the levirate obligations); Rahab (who was a prostitute), Ruth (the Moabitess descendant of the incestuous union of Lot and one of his daughters); and the wife of Uriah, Bathsheba (the adulteress) -- but also in those who are not mentioned, such as Jezebel, because the kings of Judah from the time of King Joash have a greater percentage of Jezebel in them than of King David. But a biological genealogy is not Matthew's concern; he is an apologist to the Jewish people, and his Old Testament quotations and allusions are more numerous than even Hebrews, Romans and Revelation. His purpose is to prove from the Bible that Jesus is the Messiah, the legal heir of King David.

Luke's interests are different; his primary audience appears to be the Greek world, and he lays great stress on the humanness of Jesus, tracing his ancestry back beyond Abraham, back to Adam. Luke uses the vague, genitive of relationship: Jesus "was the son, so it was thought, of Joseph, the son of Heli." (Luke 3:23) One should notice that Luke says, "so it was thought," because Luke, too, makes it plain that Mary was a virgin (Luke 1:26-37). The New International Version's use of the phrase "the son of" is an interpretive translation of Luke's phraseology, because Luke's original Greek text does not actually tell us who Heli is in relation to Joseph. However, many of Luke's readers would probably have known what that relationship was because the Jewish Talmud implies that Heli is the father of Mary, and therefore the father-in-law of Joseph. (John Lightfoot, Hebrew and Talmudical Exercitations upon the Evangelist St. Luke, Oxford: 1859, p. 55.) Luke is giving Jesus' biological genealogy. He is the son of Mary, the daughter of Heli, a descendant of King David, not through his son, Solomon, but through his son, Nathan.

Legally, Jesus is the son of David through the royal line coming down to his lawful father, Joseph, according to Matthew. Biologically, according to Luke, Jesus is the son of David through his mother, the Virgin Mary. So both genealogies are important to our understanding of who Jesus is.

It is also important to affirm the fact that the Mother of our Lord did not have sexual relations until after she had given birth to the Lord Jesus; in other words, Mary was a virgin when she conceived him. All Christians historically have accepted this truth. There is no biblical reason whatsoever to question the virgin conception of our Lord. The only reason that anyone has ever questioned this is because of bigotry against the possibility of miracles. Christians may disagree over a lot of things, but this issue of our Lord being born of the Virgin Mary is a theological watershed, with believers on one side and unbelievers on the other.

For more on the virginity of Mary, you may want to read "Perpetual Virginity and Tradition" linked below.