Historically, there have been three approaches to answering the question, “Who are the brothers and sisters of Jesus?” One view is the Hieronymian view, which is the predominate Roman Catholic view, named after Jerome, one which holds that the brothers and sisters were not uterine siblings of Jesus, but were near-relatives, such as cousins. There are many problems with this approach, not the least is that there is no single example of the terms αδελφος (brother) and αδελφη (sister) ever being used, in biological/familial contexts, denoting anything other than an uterine brother or sister in either the Greek New Testament or the documents of the New Testament era. Some apologists for this perspective, including Jerome in his work, “Against Helvidius,” point to the LXX, where αδελφος is used to denote non-sibling relationships, such as that of Lot and Abram (Gen 14:14). This notwithstanding, the argument is a failure on exegetical and linguistic grounds. Firstly, the LXX would often woodenly follow the underlying Hebrew, translating the Hebrew term (which, at the time, had a wider semantic meaning that uterine sibling) אָח as αδελφος. Moreover, the relationship between Lot and Abram is qualified in verse 12, “And they took Lot, Abraham’s brother’s son . . .” Such qualifications vis-à-vis the relationship between Jesus and his brothers/sisters are absent in the biblical texts. Additionally, to foist the semantic meaning of αδελφος from the LXX era into the Greek New Testament is to commit an interpretive fallacy called “semantic obsolescence,” where one reads into a term a meaning it used to have in a previous age but no longer does (see the discussion of this in D.A. Carson’s book, Exegetical Fallacies or James Barr’s The Semantics of Biblical Language for instance). This is common in diachronic approaches to words and phrases, but more responsible Greek and Hebrew exegetes realise the weakness of this approach, and embrace a more synchronic approach to the semantic force of terms and phrases these days (it is one of the “downsides” of Kittel’s 10-volume Theological Dictionary of the New Testament, as good a resource it is). Furthermore, Koine Greek has a number of terms that denote a near-kinsman, a cousin, and other relationships, such as such as συγγενις and ανεψιος, terms that are used in the Greek New Testament (Luke 1:36 and Col 4:10). One must charge the New Testament authors with sloppiness if Mary was a perpetual virgin and such as teaching is a dogma of the faith, as Roman Catholicism and Eastern Orthodoxy teaches.
Another view is that of the Epiphanian view, named after Epiphanius of Salamis, author of works such as the Panarion. This perspective holds that the brothers/sisters of Jesus were children of Joseph from a previous marriage, and that they were the step-brothers and sisters of Jesus. This perspective appears rather early. The first attestation I can find would be the Protoevangelium of James, where Joseph is presented as an aged man and promises to be the protector of Mary (in this text, Mary was a temple virgin who, after entering maturity, could no longer dwell in the temple). Their marriage was arranged by Zechariah, the father of John the Baptist. Interestingly, this text provides the purported names of Mary’s parents, Anne and Joachim, both canonised saints in Catholicism. This is a minority position today, though it is held by a leading NT scholar, Richard Bauckham (though I should point out, Bauckham does not hold to perpetual virginity). One of the key “proof-texts” of this view is John 19:26-27, which I will exegete later in this post. At least one Latter-day Saint scholar holds to this view, too (Jeffrey Chadwick).
The third view, which is, functionally, the Latter-day Saint perspective (I say “functionally” as, notwithstanding there being no official declaration on this issue from the Church, I am unaware of any Latter-day Saint, with only one exception [Jeffrey Chadwick, mentioned above], who doesn’t hold to this view) is the Helvidian view, named after Helvidius, an early opponent of Mary’s perpetual virginity (a teaching that is tied heavily into the origins of these theories regarding the identity of Jesus’ brothers/sisters). The main strength of this position is that it allows for a more natural, exegetically sound meaning of, not just the terms αδελφος and αδελφη in the New Testament texts, but also makes more exegetical sense of texts that clearly refute the thesis of Mary being a perpetual virgin (Matt 1:18-25). Furthermore, it allows for prima facie (and even secunda facie) reading of the pertinent texts and does not require one to engage in special pleading by foisting an unnatural meaning of key terms onto the biblical data.
Let us now engage in some of the biblical data itself.
The Gospel of Matthew makes explicit reference to the “brothers” and “sisters” of Jesus in two key texts:
While he yet talked to the people, behold, his mother and his brethren stood without, desiring to speak with him. Then one said unto him, behold, thy mother and thy brethren stand without desiring to speak with thee. But he answered and said unto him that told him, Who is my mother? And who are my brethren? And he stretched forth his hand toward his disciples, and said, behold my mother and my brethren! For whosoever shall do the will of my Father which is in heaven, the same is my brother, and sister, and mother. (Matt 12:46-50)
And when he was come into his own country, he taught them in their synagogue, insomuch as they were astonished, and said, Whence hath this man this wisdom, and these mighty works? Is not this the carpenter’s son? Is not his mother called Mary? And his brethren, James, and Joses, and Simon, and Judas? And his sisters, are they not all with us? Whence then hath this man all these things? (Matt 13:54-56)
It is the former pericope, Matt 13:46-50, that I will focus upon here. In this pericope, Jesus establishes what is called an “eschatological family,” one that is not based on biological ties one has with another, but on spiritual ties. If the Hieronymian view is correct, and we are to interpret “brothers” and “sisters” as cousins/near-relatives, it makes nonsense of Christ’s comments. When we enter a salvific covenant with the Lord, we become the brothers and sisters of Jesus, not his near-kinsmen, spiritually. The biological meaning of brothers/sisters must have a one-to-one correspondence to the spiritual brothers/sisters for this pericope to be internally consistent and also to make exegetical and theological sense.
One “counter” to this view, as well as a popular defence of the Epiphanian view (cited by the likes of Bauckham and Chadwick) is John 19:26-27:
When Jesus therefore saw his mother, and the disciple standing by, whom he loved, he saith unto his mother, Woman, behold thy son! Then saith he to the disciple, Behold thy mother! And from that hour that disciple took her unto his own home.
Critics of the Helvidian view argue that Jesus would not have entrusted the care of His mother to the beloved disciple unless he had no biological siblings who could care for this mother. However. This view ignores fact that John presents the siblings of Jesus as being vocal unbelievers, as well as being absent from the crucifixion (they would only later become believers, as evidenced in Acts 1:14). Note, for instance, John 7:1-5:
After these things Jesus walked in Galilee: for he would not walk in Jewry, because the Jews sought to kill him. Now the Jews’ feast of tabernacles was at hand. His brethren (αδελφος) therefore said unto him, Depart hence, and go into Judaea, that thy disciples also may see the works of thou doest. For there is no man that doeth anything in secret, and he himself seeketh to be known openly. If thou do these things, shew thyself to the world. For neither did his brethren (αδελφος) believe in him.
The Hieronymian view, which interprets αδελφος in this pericope to be a cousin/near kinsman makes nonsense of the biting irony and tragedy of John 7:5, wherein the closest family members of Jesus reject His message (“not even his cousins believed in him”?) As with many other key texts, only the Helvidian view makes exegetical sense of the data.