In this post, I want to address one of the most significant Protestant claims against Catholic teaching: the siblings of Jesus.
The Catholic Church asserts the perpetual virginity of Mary, teaching that she was a virgin for her entire life and had no other children besides Jesus. Catholics hold that the individuals referred to as Jesus’ “brothers” in Scripture were actually His extended kin or cousins. There is substantial evidence supporting this interpretation, and I hope to demonstrate in this article why it remains the strongest argument in this debate.
Protestants often assert that Mary had other children, pointing to verses such as Matthew 1:25 with the word “until”. See my blog post on Unpacking ‘Until’ for why this fails. Protestants also appeal to other biblical references to Jesus’ “brothers.” For example, a commonly cited Protestant apologetics site bible.ca claims:
“The term brother is never used in the New Testament to denote a cousin or relative or anything other than a literal BROTHER.”
This argument is widely used and I want to show it fails to consider the linguistic, context of the Scriptures. Understanding these aspects is key to resolving the question of Jesus’ “siblings.”
The Term “Brothers” in Scripture
First, let’s address the term “brothers.” Admittedly, the most straightforward reading of the text suggests that Jesus indeed had biological brothers or siblings. However, as with many passages in Scripture, the simplest reading is not always the correct one.
For instance, in Matthew 5:29-30, Jesus says, “If your right eye causes you to sin, pluck it out and cast it from you.” A literal interpretation of this passage would lead to self-mutilation. Yet, we understand this to be hyperbolic language, emphasizing the seriousness of sin rather than a directive to harm oneself.
Similarly, Genesis 6:6 states, “The Lord regretted that He had made man on the earth.” A plain reading implies that God changes His mind, but this contradicts other passages affirming God’s immutability, such as Numbers 23:19. The Genesis passage reflects God’s grief over sin, expressed in human terms for our understanding, not a literal change of mind.
With these examples, we see that a surface-level reading of Scripture often leads to incorrect conclusions. To understand the term “brothers” in the Gospels, we must examine it in its cultural, and linguistic contexts.
What Language Did Jesus Speak?
Jesus is commonly noted for being a Jew, so I think it’s more than fair to say Jesus knew Hebrew.
There’s also a plethora of evidence that he spoke Aramaic. Most religious scholars and historians agree with Pope Francis that the historical Jesus principally spoke a Galilean dialect of Aramaic. Source.
It is also worth noting that, setting aside my personal belief in His divinity, it is plausible that Jesus spoke some Greek. This assumption is supported by the proximity of Greek-speaking regions and the fact that the New Testament was written in Greek. “Jonathan Katz, a Classics lecturer at Oxford University, told BBC News that Jesus likely did not know more than a few words of Latin. He suggests that while Jesus probably had some knowledge of Greek, it was not the primary language of the people He interacted with regularly, and He was likely not highly proficient in it.” Source.
For the sake of the argument I’ll even admit this is debated and let’s assume he didn’t speak Greek . We know for a fact he spoke at a minimum Hebrew and Aramaic. This simply fits the time and place of the historical figure that is Jesus.
Is There a Word for “Cousin”?
No. In Hebrew and Aramaic, there is no distinct word for “cousin ” as we understand it today.
Instead, the term אָח (’ach) in Hebrew and אֲחָא (’acha) in Aramaic, commonly translated as “brother,” was used broadly to describe various familial relationships, including cousins, nephews, and other close relatives.
For example in the Hebrew, in Genesis 14:14: Abraham refers to Lot as his “brother” though Lot is explicitly identified as Abraham’s nephew in Genesis 11:27 through lineage. The Hebrew word אָחִ֑יו (’achiv) means “his brother” but it is used broadly in Scripture to describe not only literal siblings but also extended family or close kin, such as cousins or nephews.
However, In Genesis 4:9, the same word אָחִ֑יו (’achiv) is used to describe Abel as Cain’s literal brother.
This flexible usage demonstrates that “brother” was often a general term for close kinship rather than strictly biological siblings.
The Term “Brother” in the New Testament
In the New Testament, written in Greek, the word ἀδελφός (adelphos)—meaning “brother” is similarly flexible.
While Protestants claim this term always refers to biological siblings, this is demonstrably false.
The same word is used ἀδελφός (adelphos) to refer to non literal brothers. In Romans 1:13: Paul addresses the Roman Christians as “brothers,” referring to their shared faith, not familial ties. In Romans 9:3: Paul refers to his fellow Israelites as “brothers,” indicating ethnic or national kinship. Acts 7:23-26: Stephen refers to Israelites as “brothers,” underscoring communal bonds rather than blood relations.
These examples illustrate that adelphos in the New Testament is not confined to the ridgid interpretation of biological brothers.
Is There Ever an Example of Adelphos Referring to Cousins?
Yes, in the Septuagint 1 Chronicles 23:21-22
The passage says the following: “The sons of Mahli: Eleazar and Kish. Eleazar died and had no sons, but daughters, and the sons of Kish, their brethren, (adelphoi), took them as wives.” Here, adelphoi clearly means cousins, as the daughters of Eleazar married the sons of Kish.
To make it even more simpler to understand, Eleazar and Kish are brothers, both sons of Mahli. This makes their children first cousins to each other. What happens in this passage?
Eleazar dies without having any sons, leaving only daughters. These daughters marry the sons of Kish, their first cousins. The Greek text calls the sons of Kish the (adelphoi, brothers) of Eleazar’s daughters. In this context, “brothers” clearly means cousins, since it refers to the children of two brothers (Eleazar and Kish).
The Best Evidence, The Rejection at Nazareth
One of the most frequently cited passages in this debate is Mark 6:1-6, where Jesus is rejected in His hometown of Nazareth. Here, He is referred to as the “carpenter” and His “brothers” are named: James, Joses, Judas, and Simon. Also note he is referenced to have at least two sisters.
- Mark 6:1-6: is the Most detailed account, mentioning Jesus as “the carpenter” and listing His brothers by name.
- Matthew 13:54-58: Parallels Mark but calls Jesus “the carpenter’s son.” And it includes brothers as well.
- Luke 4:16-30: Provides a different perspective, focusing on Jesus reading from Isaiah in the synagogue, followed by the crowd rejecting Him. He does not mention brothers at all in his gospel, possibly indicating the Catholic position that these were not his brothers at all.
While these parallels offer insight, let’s start with Mark 6 to examine the evidence more closely.
Did Jesus Have Biological Siblings? A Closer Look at Mark 6
Mark 6:3-4 says the following:
“Isn’t this the carpenter, the son of Mary, and the brother of James, Joses, Judas, and Simon? And aren’t His sisters here with us?” So they were offended by Him. Then Jesus said to them, “A prophet is not without honor except in his hometown, among his relatives, and in his household.”
At surface level, this passage seems to suggest that Jesus had brothers, right? Not so fast. A closer look at the text, particularly Jesus’ response, shows that these alleged “brothers” and “sisters” were not His biological siblings.
The Significance of Jesus’ Response
In this passage, Jesus identifies three categories:
1. Countrymen (those in His hometown).
2. Relatives (His kin or extended family).
3. Household (those living under the same roof).
Jesus uses the Greek word syngeneusin (συγγενεῦσιν) to refer to His relatives. This term means “relatives” or “kinsfolk” and is never used anywhere in Scripture to refer exclusively to biological siblings. Instead, it always refers to extended family or kinship relationships. A challenge for those who claim that these were Jesus’ biological siblings is to point to an instance in the New Testament where syngeneusin refers to actual siblings. As far as the Greek language and biblical usage go, this term does not support that interpretation.
In contrast, the Greek terms ἀδελφός (adelphos) for “brother” and ἀδελφή (adelphē) for “sister” are used in other passages to describe both literal siblings and, depending on context, extended relationships. This flexible usage is key to understanding that the term syngeneusin in Mark 6:4 is referring to extended family, not literal siblings.
The presence of syngeneusin in Mark 6:4 makes it blatantly clear that the “brothers” and “sisters” mentioned earlier were not literal siblings. So when Protestants ask, “Why do you reject Jesus had literal brothers and sisters?” It is in fact Jesus’s very response that leads Catholics to that belief.
Some may still reject this interpretation, arguing that this isn’t sufficient evidence. To address this objection, let’s take a deeper look into the argument.
The Problematic Protestant Interpretation.
Even if one insists that the “brothers” mentioned earlier are biological siblings, they must fit into one of the categories Jesus gives: countrymen, relatives, or household members. This is the challenge: group the characters in the context into the provided categories.
When we look, this interpretation creates inconsistencies, look at the following Protestant grouping:
• Countrymen: The people in the crowd.
• Relatives: (Left empty-who fits here?).
• Household: Mary and Jesus’ alleged brothers, and sisters.
This grouping leaves the “relatives” category empty, which is an issue because Jesus explicitly mentions this as a distinct group.
Notice below how the Catholic grouping fits the categories perfectly, respecting both the linguistic flexibility of terms like adelphos and the cultural context of family structures in ancient Jewish society.
• Countrymen: The people in the crowd.
• Relatives: The “brothers and sisters” of Jesus (understood as extended kin).
• Household: Mary.
What About Unmentioned Relatives?
Some may argue that the “relatives” category could refer to unmentioned family members, such as Jesus’ aunts, uncles, or cousins, rather than the “brothers” and “sisters” explicitly mentioned earlier. This is a plausible explanation regardless if you must appeal to some unknown, unmentioned characters not suggested by the text. In this case, we can have the following categories.
• Countrymen: The people in the crowd.
• Relatives: Unmentioned extended family members.
• Household: Mary, Jesus’ alleged brothers, and sisters.
While this interpretation is technically possible, it leads to significant practical and cultural issues when examined closely.
For the sake of the argument let’s accept this is the actual definition of the text and let’s analyze this information. Lets see what we’d have to accept if these siblings actually lived in the same household as Jesus.
*Note also that the text does not distinguish between brothers and sisters in any way, so it would be problematic to assume that some are biological siblings and others are extended kin.
Scenario 1: Mary Had Children Right Away After Jesus
If Mary began having children right after Jesus, by the time of His public ministry, she would have had at least seven grown adult children: four brothers (James, Joses, Judas, and Simon) and at least two sisters
If Mary began having children immediately after Jesus, the oldest of these “siblings” would be around 28 years old, and the youngest would still be 15 by the time of Jesus’ ministry. In the context of Marks gospel… This means 7 grown adults, including fully independent men, are all still living under their mother’s roof.
In order to take this view you must assert that 7 grown adults are living in the same household as Jesus. This is implausible for seven grown adults, particularly independent men, to still be living under their mother’s roof in Jewish culture. Grown men typically married and formed their own households.
Simply put a household of eight adults does not fit the meaning of “household” in ancient Judea, which referred to elderly parents and young dependents—not independent adults living together.
This doesn’t take into account if any of the adults had children, making it less likely that they lived under the same roof as it would just expand the household size.
In my opinion, this scenario would be the most likely as Mary would need to have 7 kids after the birth of Jesus from her husband Joseph. This would give Mary and Joseph at a minimum of 12 years to accomplish this because Joseph is last mentioned during the temple visit when Jesus was 12 (Luke 2:41-50). After this, he is notably absent from Jesus’ adult life and ministry.
The dilemma is still present however, Mary would need to have 7 grown adults living under the same roof as her. Very unlikely.
Scenario 2: Mary Had Children Later In Life
Even if we grant the most generous assumptions, the Protestant position leads to conclusions that are not only impractical but culturally absurd.
Let’s assume Joseph is still alive during Jesus’ ministry. Taking into account the context of Jewish life, Jewish men typically married in their late teens to early 20s, while women (like Mary) often married in their mid-teens. If Joseph was in his early 20s when he married Mary (likely aged 13-15), he would have been about 20-25 years old when Jesus was born.
By the time of the temple visit, when Jesus was 12, Joseph would have been approximately 32-37 years old, and Mary around 23-27. This age range is still young enough for Mary to have more children, but for this scenario to work, Mary would need to have seven children back-to-back, year after year, immediately after the temple visit.
By the time Jesus begins His ministry at around 30 years old, Joseph (if alive) would be about 50-55 years old, and Mary approximately 45. The ages of the hypothetical siblings would be as follows:
• Child 1: 17 years old
• Child 2: 16 years old
• Child 3: 15 years old
• Child 4: 14 years old
• Child 5: 13 years old
• Child 6: 12 years old
• Child 7: 11 years old
This means that during Jesus’ ministry, His supposed “brothers” would have been teenagers or even younger. Yet, these siblings are portrayed in the Gospels as engaging in adult conversations about Jesus’ mission. For example, in John 7:3-4, Jesus’ “brothers” advise Him about public recognition, a level of involvement entirely implausible for children or adolescents. Would a Jewish rabbi—or anyone in Jewish society—seriously recognize the authority or reputation of a child under 13?
The Protestant view demands that these siblings, most of whom would have been minors, were not only publicly known figures but also advising Jesus, their 30-year-old elder brother, on matters of ministry and public life.
In Mark 6:3, their names are explicitly listed, and in John 7, they critique and give advice to Jesus. This directly contradicts the rigid social hierarchies of Jewish culture, where younger siblings—especially those underage—would never critique or advise an elder sibling, let alone one of Jesus’ stature.
In Jewish society, influence rested with the rabbis, elders, and senior family members. Younger siblings, particularly pre-teens or teenagers, would not have been treated as equals to a firstborn son in His prime. Even in a small town like Nazareth, social norms mattered. The idea that these “brothers” were teenagers or younger, critiquing and advising Jesus, is not only unlikely but culturally impossible.
Even if we ignore the implausible notion of Jesus, His parents, and seven siblings all living under one roof—something already at odds with Jewish cultural norms—we are still faced with an equally problematic scenario. Teenagers advising their 30-year-old brother in public matters is simply not consistent with the cultural, historical, or textual context. This view cannot withstand scrutiny.
Which Hill Will Protestants Die On?
The Protestant position ultimately leaves two problematic options:
1. Accept that seven independent adults, including grown men, were all living at home with their mother, a scenario entirely out of place in Jewish culture.
2. Claim that Mary had pregnancies into her 30s and that her teenage children were engaging in adult civil matters, which contradicts cultural norms.
For example, if Mary had these children back-to-back after Jesus’ Temple Visit, we’d have a scenario where a group of 17-, 16-, 15-, and 14-year-old boys had enough reputation to be named during a civil matter in Mark 6:3, while their 12- and 11-year-old sisters are also publicly acknowledged. These same children would then advise their 30-year-old brother on public ministry in John 7:3-4, an absurdity in the rigid Jewish social structure where younger siblings, especially children, would never challenge or advise their elders.
The Protestant interpretation of Mark 6:3-4 creates more problems than it solves. It contradicts the linguistic, cultural, and practical realities of the time.
In contrast, the Catholic interpretation—where Jesus’ “brothers” and “sisters” are understood as extended kin—fits seamlessly with both the text and Jewish cultural norms. This interpretation also respects the linguistic nuances of adelphos and the distinct categories Jesus identifies in His response.
Which hill will Protestants die on? Neither option aligns with Scripture, history, or logic. The Catholic understanding stands as the only coherent and consistent interpretation.
But What About “Household” Only Being Used in Matthew 13?
Some argue that Matthew 13:55 only references Jesus’ “household” and does not mention relatives, raising questions about the Catholic position. Let’s break this down.
First, to assert this interpretation, you must assume that Mark’s Gospel (6:3), which mentions “relatives” (syngeneusen), is inaccurate. This creates a conflict not with Catholics, but with the consistency of the Gospel accounts themselves.
Second, while one could argue that “household” doesn’t necessarily mean those living under the same roof, this doesn’t resolve the deeper issues. If these “brothers” were older siblings, their absence in key moments of Jesus’ early life remains unexplained:
• During the flight to Egypt (Matthew 2:13-15) and the return to Nazareth, no other children are mentioned traveling with Mary and Joseph.
• At the temple visit when Jesus was 12 (Luke 2:41-50), no siblings are mentioned, even though they would have likely been present at such an important family event.
The silence about older siblings strongly suggests Jesus was Mary’s only child during this time.
Furthermore, in Jewish culture, the firstborn son held a position of honor and responsibility. If Jesus had older brothers, they—not Jesus—would have been expected to care for Mary. Yet at the crucifixion, Jesus entrusts Mary to the Apostle John (John 19:26-27), saying, “Behold your mother,” not instructing John to tell His supposed brothers. For Protestants to maintain their position, they must accept the unlikely scenario that:
1. Mark’s Gospel is inaccurate.
2. Jesus’ brothers were present during His ministry but entirely absent from His early life and key family events.
3. Despite having brothers, Jesus entrusted Mary to an unrelated apostle, which would have been culturally inappropriate unless He had no biological siblings.
This interpretation is difficult to reconcile and appears unlikely.
But Jesus Was The “First Born”!
As Catholic Answers mentions: Fundamentalists claim Jesus could not be Mary’s “first-born” unless there were other children that followed him. But this shows ignorance of the way the ancient Jews used the term. For them it meant the child that opened the womb (Ex. 13:2; Num. 3:12). The first male child of a marriage was termed the “first-born” even if he turned out to be the only child.
Even If One Were To Reject All of The Previous Evidence…
Regardless of everything we’ve discussed, if one still insists that Jesus had biological brothers, despite the overwhelming evidence to the contrary, this position still has significant holes.
1. Are Any of Jesus’ Brothers Referred to as the Children of Mary?
Nowhere in the Gospels are James, Joses, Simon, or Judas explicitly called the children of Mary. Instead, Mark 15:40 refers to “James the Less and Joses” as the sons of another Mary, clearly distinguishing them from Jesus’ mother.
2. Do the Gospels Ever Mention Mary Having Other Children?
The Gospels are silent on Mary and Joseph ever having other children. There is no mention of Mary being pregnant again after Jesus or of her having additional children. In fact, the Gospels consistently refer to Jesus as “the son of Mary” (e.g., Mark 6:3), with no indication that she bore other children.
