Paul is well known to be the earliest Christian author. In the earliest copies we have of Paul’s writings, he frequently uses the Greek word “adelphos”, just as he’s done in this case. The question is whether Paul’s use of the word “adelphos” here is a reference to a biological sibling.
Paul used the term “adelphos” every time he referred to any member of any Christian group! So, while Paul in Galatians refers to James as the Lord’s “adelphos”, only in English translation can Paul’s personal usage of this 1’st century Greek term be conflated with a biological sibling, and only then if one is also lazy and fails to employ critical thinking.
One of Paul’s many goals (certainly at least in the ahistoricist view) was to synthesize the various Jesus stories that arose from Q, conflations of fables and parables and sayings of Cynic and Stoic philosophers and sages and other itinerant preachers and teachers, Jewish Wisdom literature, the accretion of myth and stories retrospectively force-fit onto the name Yeshua/Jesus, and the so-called “Mystery Cults” (the Gnostics and so on) of the day, who had long already adopted the term “adelphos” to refer to initiates of those gnostic and other mystery cults. Paul, who was a scholar possessed of enormous philosophical and theological knowledge, brought that meaning of the word into his writings as well as the mere courteous title “adelphos”.
In 1 Corinthians 1:1, Sosthenes is called adelphos, and in Colossians 1:1, so is Timothy. And in Corinthians 15:6, 500 adelphos receive a spiritual vision of the risen Christ. Are they biological siblings of Jesus? Of course not!
That alone makes it essentially impossible for James to have been a biological sibling of Jesus, for if he had been, Paul would have used a different description to distinguish James from Sosthenes, Timothy, and 500 other people (no doubt many women among them), none of whom could be Jesus’ siblings!
So when we encounter the English phrase “James, the brother of the Lord” (not “James, the brother of Jesus”!) in Galatians 1:19 and recognize that Paul once again used the term “adelphos”, it is foolish to contend that Paul meant that James was Jesus’ biological sibling.
Some will object: “Paul does put special emphasis on James and his relationship to the Lord. How do you explain that?”
Like this: The evidence strongly suggests that James was the head of one particular Christian group in Jerusalem which focused exclusively on the spiritual Christ, as opposed to Jesus the alleged human teacher or minister (that also makes it tremendously unlikely that James would be Jesus’ sibling). This group called themselves the “Adelphos of (or “in”) the Lord”. The leader of this group, whomever he or she was at any specific time (early Christians saw no problem with women leaders, to their great credit), was apparently given the official title that was translated into English as “The brother of the Lord”. It was an honorary title, not a description of a biological sibling relationship to Jesus the man.
Again, that last is also made clear by the references to “brother of the Lord” rather than to “the brother of Jesus”.
But what of the writings of others beside Paul? What are we to make of their references to James?
Let’s look at the epistle named for him. While no knowledgeable biblical scholar still believes that this is a genuine Pauline epistle (or even written by this James), it is instructive to look at the opening line, which reads in English: “James, a Servant of God and of the Lord Jesus Christ…” If James was thought by the author to be in fact the biological brother of Jesus the man, why is he referred to there as the Lord Jesus Christ’s “servant” and never even his brother or adelphos at all?
And then let’s look at the epistle of Jude. That opens by describing Jude as “a servant of Jesus Christ, and a brother of James”. While the Gospel of Mark 6:3 identifies Jude (and others) as the adelphos of James (implying that both Jude and James are the biological siblings of Jesus), had they been thought to be so in Paul’s day 20 years or so before Mark was written, they would have been described as such, but they were not so described until the (fictional, in my view) Gospels!.
There were a great many frustrating and polarizing differences in the beliefs and teachings of the church among the early Christian communities (as Paul’s genuine epistles abundantly documents), and there would be no better way to bring more order to all the massive disorder than for a true biological sibling of Jesus the man to be clearly identified as a primary authority. The Jews thought bloodlines and family trees were extremely important. For just one example, who qualified for the priesthood was considered to have enormous importance, and since the priesthood was purely inherited from family members, had a member of Jesus’ biological family been known or had come forward, he or she would have had enormous power to unite the highly fractious and angry bunch of wildly different beliefs and tenets and theologies all over the place. Those communities would have rejoiced to have had a member of Jesus’ family leading them. The Jewish early Christians, of that age at least, were highly authoritarian and would have loved nothing more than an authority figure based on the most fundamental basis: birth and bloodline. But they could find no one like that at all.
No relative of Jesus is ever identified by anyone in the early, pre-Gospel Christian world. Even if such a person were to have been reluctant to exert any authority or even to receive some minor recognition, he or she would have been identified anyway, since someone else would claim authority by proxy by dint of his friendship with Jesus or with one or more of Jesus’ biological siblings.
But no relative of Jesus was ever identified or claimed prior to the Gospels!
The Evangelists merely assumed James and Jesus were siblings, based mainly I suspect on the fact that there simply was no way to distinguish between the several different meanings of the Greek word “adelphos”.
Which bring us to references to Peter/Cephas. Again, we must turn to Paul, for Paul is the single earliest New Testament writer, predating by two decades even the first Gospel to be written, which the largest scholarly consensus identifies as Mark and dates to ~ 72 AD.
Paul refers to Cephas as an “apostle” (though only once), as do the canonical Gospels. But the Gospel’s “apostles” are a group of twelve men, and that Cephas/Peter was one of them. How does Paul refer to the “apostle” Cephas?
He refers in 1 Corinthians 15:5-7 to a group who had a msytical vision of the risen Christ (not Jesus the man), and writes that “… he was seen by Cephas, and afterward by the Twelve … then he was seen by James and afterward by all the apostles”.
This tells us that although the vision was reportedly seen by Cephas, he was not one of “the Twelve”, and further that there were more “apostles” than just “the Twelve”. Bottom line, Cephas was not one of a group of twelve apostles but was instead just one of a large group of many apostles. There’s no credible reason at all to think that Cephas ever knew Jesus the alleged man. So the fact that Cephas is, at least 30 years later, referred to in the Gospel of Matthew as the “rock” upon which Christ will build “His Church”, it’s abundantly clear that either this Cephas is fictional (as I contend Jesus is) or Matthew’s Peter and Paul’s Cehphas are just not the same guy.
This is further revealed by all the bitter disputes between Paul and Cephus and many of the rest of the “apostles”, including “the Twelve”, the title apparently given to a more “select” group of the many “apostles” (note that Paul insists that he was an apostle, too). Both the title “apostle” and the title “the Twelve” appear, again, to be honorary titles rather than descriptive ones (think of them in light of the special group of twelve Mormon “apostles”, for example). Because if “the Twelve” were actually the direct followers of a biological Jesus (as a literal reading of the Gospels would have it), who would dare argue with such holy personages and criticize them as forcefully as Paul so often did?
Look at how important bloodlines are in terms of the leaders of religious sects when the original leader dies or is otherwise removed from the scene, such as we see in Islam and in Mormonism. The blood relative doesn’t necessarily end up the sole or primary leader, but the blood relative is an extremely important and noted personage in the remaining movement or splinter movement.
No, had James been a blood sibling of Jesus, he would have been celebrated as such and would have been seized upon as an authority by dint of his bloodline, or someone else would have capitalized on being the friend or special associated of the blood relative. Sociobiology is powerful indeed in such situations, as religious history has shown over and over again.
Recall that Paul was an avid persecutor of the “Son of God” faith, and like all zealous anti-zealots, the blood relations of any alleged “founder” of such a faith would be subject to special attention and control. But Paul never indicated any such special attention. Instead, he refers to both James -and- Cephas as “adelphos”, showing no special interest in James as he would have done if James were a biological sibling of Jesus. Over and over again, a biological sibling would absolutely have been repeatedly called upon to interpret his biological brother’s words and ideas, just as we see pretty much whenever there is a biological relationship to call upon.
While the Jerusalem Church headed by James as “the” adelphos of “the Lord” (never adelphos of Jesus!) was important, it was by no means the central authority of the new church, which instead was Paul. That’s simply not credible if James has been a biological sibling of Jesus.
James’ group in Jerusalem had the following name: Adelphon en Kurio, “Brothers In the Lord”. Never are they called “Brothers in Jesus”. This is strong evidence that no historical or other Jesus was known of or referenced, else they would have either named themselves The Brothers of Jesus or they would have written or asked James or Paul about this Jesus, but there’s no evidence that never happened. It seems clear that his was a church that worshiped a spiritual Lord rather than any historical figure. If “Adelphon en Kurio” referred to biological siblings, they would all have to be biological siblings of some unnamed “Lord”! One cant’ arbitrarily claim adelphos means “biological sibling of Jesus” in certain instances but “members of a like-minded community who believed in a spiritual Lord” in others.
Arguing that a tiny difference in one passage can only mean a reference to a biological sibling is quite absurd and fallacious given that this is never followed up upon. Had James been a biological sibling, much more would have followed, including the kind of special treatment I’ve already described. It’s far too little a thing to base a historical argument upon given all the changes made by copyists that Ehrman brings out in his book Misquoting Jesus.