Jesus had no blood brothers or sisters.
But wait, doesn’t it says right there in Mark 6, which we read today:
3* Is not this the carpenter, the son of Mary and brother of James and Joses and Judas and Simon, and are not his sisters here with us?” And they took offense * at him.
This is why scripture alone does not give us a full picture. Context is key. Context is informed by history, tradition, and linguistics.
First, in ancient Hebrew the word for “brother” has a broader meaning then “blood brother”. Further there were no words in their language for more distant relationships like “cousins”. To describe someone relationship specifically you would have to use a circumlocution – like “he is the son of my wife’s sister”. This is obviously cumbersome, especially in writing, and thus the word “brother” is often used to describe familial relationships that are one step further removed then blood brothers, i.e., cousins.
Second, notice that when other people are referred to brothers of the Lord they are never referred to as “sons (or daughters) of Mary” in the New Testament texts. Only Jesus is ever referred to as the “Son of Mary”.
Third, we see in context that Paul called James as a brother of the Lord and an Apostle
19 But I saw none of the other apostles except James the Lord’s brother.
However, when the Apostles are identified there are two (2) named James. One’s father is Zebedee and the father of the other Is Alphaeus.
Mark 3: 12 -19 And he appointed twelve (whom he also named apostles) so that they might be with him and he might send them out to preach 15 and have authority to cast out demons. 16 He appointed the twelve: Simon (to whom he gave the name Peter); 17 James the son of Zebedee and John the brother of James (to whom he gave the name Boanerges, that is, Sons of Thunder); 18 Andrew, and Philip, and Bartholomew, and Matthew, and Thomas, and James the son of Alphaeus, and Thaddaeus, and Simon the Zealot, 19 and Judas Iscariot, who betrayed him.
In fact, James and Joseph (“Joses” in today’s reading / above) are elsewhere identified as sons of a different Mary in the Gospel.
Matthew 27: 55 There were also many women there, looking on from afar, who had followed Jesus from Galilee, ministering to him; 56* among whom were Mary Magdalene, and Mary the mother of James and Joseph, and the mother of the sons of Zebedee.
Mark 15: 40* There were also women looking on from afar, among whom were Mary Magdalene, and Mary the mother of James the younger and of Joses, and Salome, 41* who, when he was in Galilee, followed him, and ministered to him; and also many other women who came up with him to Jerusalem.
Finally, and MOST IMPORTANTLY, just before he gives up his life on the cross Jesus entrusts his mother Mary to the care of the Apostle John.
John 19: 26* When Jesus saw his mother, and the disciple whom he loved standing near, he said to his mother, “Woman, behold, your son!” 27 Then he said to the disciple, “Behold, your mother!” And from that hour the disciple took her to his own home.
Under Jewish law if Mary had any other male children she would have immediately passed into their care upon the death of her oldest “first-born” son, Jesus. If Mary had other male children, (i.e., blood brothers of Jesus) it would have been completely unnecessary for Jesus to give his mother into the care of John. In fact, it would have been a great insult to his brothers and a violation of the old covenant law (which was still in effect at the point) for Jesus to pass the care of Mary to John. Of course, Jesus would not have done anything to dishonor his mother or that would have failed to fulfill the old covenant. Jesus giving Mary into John’s care only makes sense if he had no blood brothers or sisters. Jesus leaves Mary in John’s care and we know from history that John went with Mary to Ephesus where they lived for a time.
Thus, the full weight of the evidence shows that Jesus had no brothers or sisters. “Brothers of the Lord” refers to people that were either extended relations or Apostles and close associates.