The genealogy in Matthew, like that in Luke, is really a genealogy of Joseph who, according to Matthew, is not even the real father of Jesus. Moreover, there is nothing about this Joseph in Mark. Even if Joseph is only Jesus’ father-in-law through his marriage to Jesus’ mother it is still an extraordinary state of affairs that (i) the Gospel of Mark makes no mention of him and (ii) the Gospel of Matthew traces the descent of Jesus through him. Was he known as Jesus’ father or was he not?

Linked to this odd role of Joseph is something even odder. The genealogy says that Jesus was born to Mary:

… and Jacob begat Joseph, the husband of Mary, of whom was begotten Jesus, who is named Christ. (Matthew 1:16)

The Greek is quite explicit that Jesus is born of Mary rather than Joseph. It is hard to overstate how odd this would have appeared to a Jew of the time when descent was always given through the male line. The sceptic regards this as further evidence that Jesus was illegitimate. In this view, the virgin birth story was developed to cover this illegitimacy. But looking at the circumstances around illegitimacy we will see that the virgin birth could not have fulfilled this function.

If Jesus were illegitimate then there would have been two possibilities. The first is that the illegitimacy was covered up, and the child was publicly accepted as Joseph’s. This is quite possible, particularly if Mary came from a good family and Joseph from a relatively poor background; he could have been induced to overlook an indiscretion in his future bride. In this case, it would have been in everybody’s interest to maintain the front that Jesus was the son of Joseph. But then he would have been called “Jesus son of Joseph” so why does the Gospel of Mark not know who his father was? There would have been no need for the virgin birth story since publicly Jesus would not have been illegitimate and to the ancient mind “face” was all that really mattered. If Joseph acknowledged him as his son, then he was his son.

The second possibility is that the illegitimacy was public because Mary was unmarried when Jesus was born. In this case, Mary would have been widely considered as a whore and subsequent marriage would have been difficult. If she were to marry Joseph, then there must have been a gap of time between the birth of Jesus and the marriage. It would have been impossible for Joseph to marry Mary while she was pregnant without acknowledging Jesus as his son. To do so would result in catastrophic loss of face. So in this second possibility, we have the situation where Mary is known to be a woman without virtue, Jesus is publicly known to be illegitimate, and Mary’s marriage to Joseph would have taken place sometime after Jesus was born. This would be consistent with the evidence from Mark that Jesus’ father was unknown. But it is not consistent with Matthew’s tracing Jesus’ descent from David through Joseph. Nor is it consistent with the virgin birth story. Jesus would have borne the stigma of illegitimacy throughout his life, and no one would have questioned the fact of his illegitimacy in his lifetime. Similarly, Mary would have long been accepted as a woman of dubious virtue. The Jesus movement would have had to live with these facts and develop strategies to adapt to them. To go back after Jesus’ death and recast Mary as a virgin mother and Jesus as the son of God would have been laughable.

The virgin birth story is not a cover for illegitimacy. Rather it is an attempt to explain something that is in Matthew’s sources, something that the author of Matthew does not understand. The author of Matthew has a source telling him that it is through Joseph that Jesus can claim descent from David. But he knows that Jesus is not Joseph’s son!

There is a second intriguing feature about the Matthew genealogy that many regard as pointing towards illegitimacy. It is normal for Jewish genealogies to give only the male line and not to mention the mothers. Yet in four instances the Matthew genealogy gives the name of the mother also. And in each of these four cases, the women named are of dubious virtue; Tamar and Rahab both prostituted themselves, and Bathsheba was an adulteress. Ruth was a widow and a Moabitess, who goes to her kinsman Boaz when he is sleeping alone at night to persuade him to marry her.

All of the woman named would be seen, by the standards of the time, as whores. What can account for this strange pattern? Those who favour the illegitimacy theory regard it as pointing to the lack of virtue of the one other woman named in the genealogy; Mary herself. Perhaps the author is trying to link her to other women in the history of Israel who played key roles as mothers while at the same time being impure. But why would the author of Matthew, who first gives us the story of Mary as the virgin mother, connect her to women who were whores?

There is one other piece of evidence that would appear to support the illegitimacy argument, and that is a saying in the Gospel of Thomas:

Jesus said: “He who shall know father and mother shall be called the son of a whore.” (Thomas 105)

Taken together with the four women in the genealogy it seems to be telling us that something is wrong about Jesus birth. But is this saying really about Mary at all? If it were about Jesus, why would such a negative saying be in the gospel? Even if Jesus were illegitimate, the sayings of the Jesus movement would not stress the fact! Also Thomas 105 talks about knowing “father and mother” which implies secret adultery. Neither the identity of the father nor the character of the mother is what we think it is. This does not fit the situation of an unmarried Mary becoming pregnant and subsequently marrying Joseph.

There is, however, a connection between the saying and the genealogy. In a normal genealogy only the male line would be named and we would know the fathers but not the mothers. However, in Jesus’ genealogy, the mothers are also named in four cases. So for these four, and these four only, we know both father and mother, as the Thomas saying says. In each of these four cases, the mother can be thought of as a whore, and the offspring as “the son of a whore”. The inclusion of the four mothers is a literal and pedantic expression of the Thomas saying!

What has happened is that someone has interpreted the Thomas saying as being about Jesus’ ancestors. So, to explain the saying, they have put the four mothers who could be thought of as whores into the genealogy. Most likely this was done by editing an earlier existing genealogy at the time it was incorporated into Matthew. It certainly shows that the Thomas saying is earlier than the Gospel of Matthew.

The four women do not point towards Jesus’ illegitimacy but are explained by the Thomas saying. This saying has been misapplied for it has nothing to do with Jesus or Mary.

(The above is an extract from Chapter 18 of The Rock and the Tower.)