We are going to take up the two genealogies again in order to compare the lists of names.
Note 1: Luke states: “He was, as was supposed, the son of Joseph, the son of Heli”. In the case of a genealogy of Mary, as we suppose, Joseph is Heli’s son-in-law and not his son as recorded by Luke. The term son frequently stood in for that of son-in-law, since the latter has no precise equivalent in Greek. We have replaced the name of Joseph with that of Mary, who is not named in Luke’s text.
Note 2: we have set Luke’s list in the same direction as Matthew’s in order to compare them more easily. We have also removed the whole part after David that Matthew does not cite.
Note 3: Matthew and Luke both record Abraham, the father of believers
Joseph’s contemporaries knew the name of his father, and are not surprised by the expression used by Luke.
In examining these two genealogies, we can observe similarities. Indeed, the same names are mentioned several times, particularly in the section from Abraham to David, which is identical in both cases.
However, we are also compelled to acknowledge that there are serious differences, which lead us to a more in-depth analysis.
Matthew cites the descendants of Solomon, the second son of David with Bathsheba, whereas Luke mentions Nathan, the third of David’s four sons with Bathsheba. From that point on, the two lines naturally diverge.
It is impossible for the same person to descend from two different lines unless it happens through a marriage and the adoption of the wife’s lineage. This option is hard to accept, which leads us to think that there were two distinct individuals.
We know that, for the Jews of that time, genealogy was regarded as an exact and precise science. As we have already pointed out, some individuals altered their ancestry at great expense in order to obtain a better status in society, but this concerned mainly wealthy people and remained exceptional.
It is therefore unthinkable that Matthew or Luke made a mistake or attempted any kind of adaptation. Indeed, the purpose of these genealogies is simply to demonstrate that Jesus can lay claim, by his ancestry, to the status of Messiah or King of the Jews.
An inaccuracy, quickly detected, would have classed Jesus as an impostor. The whole argument of Matthew’s account would collapse in that case.
We must not overlook the fact that the religious leaders, who ruled the country and were strongly opposed to this new doctrine, certainly did not fail to verify the credibility of these claims in their research. Indeed, even though Matthew had not yet written his genealogy, the Messiah Jesus was often called son of David, which did not fail to challenge his opponents Matthew 12.23.
This wording appears 22 times in the Gospels.
How can we explain the differences between the information given by Matthew and that given by Luke?
The most fitting answer, and now the most widely recognized, is that Matthew presents to us the genealogy of Joseph, the legal father, whereas Luke describes that of Mary, the biological mother.