Two of Jesus’ “brothers”—James The Just and Jude—also authored books of the New Testament. There have been attempts to identify them with the Apostles known as James Son of Alphaeus and Jude Thaddeus.
However, this is implausible, because John’s Gospel unambiguously indicates that Jesus’ “brothers” were not disciples during his ministry, stating, “even his brothers did not believe in him” (John 7:5). It is thus scarcely likely that two of them were among the apostles that followed him during his ministry.
We thus can’t use the average age of Apostles to determine the age of these two figures. However, we may be able to determine their probable ages in another way. If the theory—common in Protestant circles—were true that they were Jesus’ younger half-brothers (born to Joseph and Mary) then we might estimate their birth years based on Jesus’ birth year. However, this view is excluded by other information we have, which indicates that Mary remained a virgin after the birth of Jesus.
Since the time of Saint Jerome, it has been common in Western Catholicism to propose that the brethren of the Lord were cousins. If so, we have no way of telling whether they were older or younger cousins (or both). We would know only that they were of the same generation as Jesus, which we could have determined anyway.
However, the earliest proposal for who were the brethren of the Lord—a proposal that dates to the A.D. 100s, making it older than either of the above views, and which has always been the view maintained in Eastern Catholicism and Eastern Christianity—is that they were Jesus’ step-brothers, that is, children of Joseph by a prior marriage. As an elderly widower Joseph was not seeking to begin a family and thus he was willing to serve as the guardian of the consecrated virgin Mary.
If so, the brethren would have been older than Jesus—but by how much?
The Gospels identify Jesus’ brethren as James, Joses (Joseph), Jude, and Simon (Matt. 13:55, Mark 6:3a). They also indicate that he had at least two “sisters” (Matt. 13:56, Mark 6:3b). We have already taken into account the effect that sisters would have had on the average gap between surviving sons, so if the above list reflects the birth order of Jesus’ brethren (as is probable), we may estimate that James was the oldest, that Joses was six years his junior, that Judas was twelve years his junior, and that Simon was eighteen years his junior.
We must also allow time for Joseph’s first wife to pass and for him to grieve and then become the husband of Mary. We will assume that this represented three years, since men with small children (as Simon would have been) tended to remarry quickly in the ancient world. After marrying, it was customary to wait a year before beginning cohabitation, and Jesus was conceived by the Holy Spirit during this period. That would give us the following estimates for the births of Jesus and His brethren:
- James: 25 B.C.
- Joses: 19 B.C.
- Jude: 13 B.C.
- Simon: 7 B.C.
- Jesus: 3/2 B.C.
Of course, these are only estimates, and Jesus’ brethren—or at least some of them—may have been born much less than six years apart. On the other hand, around A.D. 378, in his Panarion, St. Epiphanius of Salamis reports a tradition that James died at the age of 96. From Josephus, we know that James was martyred in A.D. 62, in which case he would have been born in 35 B.C., so the above estimates might be too late rather than too early.
Either way, however, the brethren would have been significantly older than Jesus, which may explain their attitude of disbelief during Jesus’ ministry. As Jesus said, a prophet has no honor in his own family. From their perspective, Jesus was the much younger son of their father’s second wife, and it took the miracle of the Resurrection to convince them that he was the Messiah. Now then, let’s have a closer look at these men beginning with: