The Family of Jesus in the New Testament by Felix Just, S.J., Ph.D.
The Tribe and Clan of Jesus:
Descendant of Abraham, Isaac, and Jacob; Tribe of Judah; Family/Clan of David:
Matt 1:1-3, 17 –
An account of the genealogy of Jesus the Messiah, the son of David, the son of Abraham. 2Abraham was the father of Isaac, and Isaac the father of Jacob, and Jacob the father of Judah and his brothers, 3 and Judah the father of Perez and Zerah by Tamar, and Perez the father of Hezron, and Hezron the father of Aram,... / / 17 So all the generations from Abraham to David are fourteen generations; and from David to the deportation to Babylon, fourteen generations; and from the deportation to Babylon to the Messiah, fourteen generations.
Matt 1:20 – But just when he had resolved to do this, an angel of the Lord appeared to him in a dream and said, “Joseph, son of David, do not be afraid to take Mary as your wife, for the child conceived in her is from the Holy Spirit.”
Matt 2:6 – “And you, Bethlehem, in the land of Judah, are by no means least among the rulers of Judah; for from you shall come a ruler who is to shepherd my people Israel.”
Matt 9:27 – As Jesus went on from there, two blind men followed him, crying loudly, “Have mercy on us, Son of David!” (cf. Matt 15:22; 20:30-31; Mark 10:47-48; Luke 18:38-39)
Matt 12:23 – All the crowds were amazed and said, “Can this be the Son of David?” (cf. Matt 21:9, 15; Mark 11:10)
Matt 22:42-45 – “What do you think of the Messiah? Whose son is he?” They said to him, “The son of David.” (cf. Mark 12:35-37; Luke 20:41-44; Acts 2:34)
Luke 1:27 – [Angel Gabriel was sent] to a virgin engaged to a man whose name was Joseph, of the house of David. The virgin’s name was Mary.
Luke 1:32 – “He will be great, and will be called the Son of the Most High, and the Lord God will give to him the throne of his ancestor David.”
Luke 2:4 – Joseph also went from the town of Nazareth in Galilee to Judea, to the city of David called Bethlehem, because he was descended from the house and family of David. (cf. Luke 2:11)
Luke 3:23, 31, 33-34 – Jesus was... / / son of Melea, son of Menna, son of Mattatha, son of Nathan, son of David, / / son of Amminadab, son of Admin, son of Arni, son of Hezron, son of Perez, son of Judah, / son of Jacob, son of Isaac, son of Abraham, son of Terah, son of Nahor,...
John 7:42 – “Has not the scripture said that the Messiah is descended from David and comes from Bethlehem, the village where David lived?”
Rom 1:3 – the gospel concerning his Son, who was descended from David according to the flesh
Gal 3:16 – Now the promises were made to Abraham and to his offspring; it does not say, "And to offsprings," as of many; but it says, "And to your offspring," that is, to one person, who is Christ.
2 Tim 2:8 – Remember Jesus Christ, raised from the dead, a descendant of David--that is my gospel,
Heb 7:14 – For it is evident that our Lord was descended from Judah, and in connection with that tribe Moses said nothing about priests. (cf. Heb 8:8)
Rev 5:5 – Then one of the elders said to me, “Do not weep. See, the Lion of the tribe of Judah, the Root of David, has conquered, so that he can open the scroll and its seven seals.” (cf. Rev. 3:7; 7:5)
Rev 22:16 – “It is I, Jesus, who sent my angel to you with this testimony for the churches. I am the root and the descendant of David, the bright morning star.”
They are celebrated liturgically on July 26 on the Roman liturgical calendar.
Parents of Joseph:
Joseph's mother is never mentioned in the NT.
Joseph's father is given two different names in the genealogies of Jesus in the Gospels of Matthew and Luke:
Matt 1:16 – "...Jacobthe father of Joseph the husband of Mary..."
Luke 3:23 – "He [Jesus] was the son (as was thought) of Joseph son of Heli" (or spelled Eli)
Joseph of Nazareth:
Joseph, the husband of Mary, is mentioned only briefly in the Gospels of Mark and John, more extensively in Matthew and Luke, but not at all in the rest of the NT.
Caution: Several other men named Joseph are also mentioned in the NT:
Joseph of Arimathea, who buried Jesus (Mark 15:43-46; Matt 27:57-60; Luke 23:50-53; John 19:38-42).
Joseph, the OT patriarch, one of the 12 sons of Jacob (John 4:5; Acts 7:9-18; Heb 11:21-22; Rev 7:8).
One of the four named "brothers of Jesus" ("Joseph" in Matt 27:56; but "Joses" in Mark 6:3).
Two other Josephs, ancestors in the Lukan genealogy of Jesus (Luke 3:24, 30).
Two other Josephs, disciples in the early Church: Joseph a.k.a. Barsabbas (Acts 1:23) and Joseph a.k.a. Barnabas (Acts 4:26).
Is Joseph of Nazareth the "Father" of Jesus?
The proper answer is both Yes and No, depending on how one defines "father":
No, Joseph is not the "natural father" or "biological father" of Jesus; the Gospels say that Jesus was conceived "through the Holy Spirit" (Matt 1:20; Luke 1:31-35).
Yes, Joseph is the "legal father" of Jesus, thus sometimes also called his "foster-father":
Not only does Joseph accept Mary as his wife (Matt 1:20-24; Luke 1:27; 2:4-5), but he also accepts legal paternity of Jesus by naming the baby (Matt 1:21, 25), rather than rejecting him.
The genealogy or heritage of Jesus as a "Son of David" and member of the "tribe of Judah" is not traced through the genealogy of Mary, but that of Joseph (Matt 1:16, 20; Luke 3:23).
The Evangelist Luke refers to Jesus' "parents" (2:48a), and Mary herself says to the 12-year-old boy, "Your father and I have been looking for you" (2:48).
Jesus is several times called "the carpenter's son" (Matt 13:55) and "the son of Joseph" (Luke 4:22; John 1:45; 6:42), but only once called "the son of Mary" (Mark 6:3).
Joseph is never named, or even alluded to, anywhere in Mark's Gospel.
While Matthew 13:55 refers to Jesus as "the carpenter's son", the parallel text in Mark 6:3 does not mention Jesus' father, but instead reads, "Is not this the carpenter, the son of Mary...?"
Jesus sometimes refers to fathers (and mothers) in general in Mark (7:10-12; 10:7, 19, 29; 13:12), but neither Jesus nor the Evangelist Mark ever refers to Jesus' earthly father.
In Mark, Jesus sometimes also refers to God as his Father (Mark 8:38; 13:32; 14:36) and once, when speaking to his disciples, also refers to God as "your Father in heaven" (Mark 11:25).
In the other Gospels, Jesus refers to God as "my/your/our Father" dozens of times in Matthew and Luke, and over 120 times in John!
Joseph is one of the main characters in the Infancy Narrative, but mentioned only once (indirectly) later in the Gospel:
Matt 1:16 – Near the end of the genealogy of Jesus: "and Jacob the father of Joseph the husband of Mary, of whom Jesus was born, who is called the Messiah."
Matt 1:18-25 – Joseph receives an angelic message in a dream about Mary having a child by the Holy Spirit.
Matt 2:13-23 – Joseph receives further messages in dreams about fleeing to Egypt and later returning from Egypt.
Matt 13:55 – When Jesus visits Nazareth, people refer to his father's occupation: "Is not this the carpenter's son?"
Joseph is mentioned only briefly and indirectly in the Infancy Narrative, and a few other times later in this Gospel:
Luke 1:26-27 – "In the sixth month the angel Gabriel was sent by God to a town in Galilee called Nazareth, / to a virgin engaged to a man whose name was Joseph, of the house of David. The virgin's name was Mary."
Luke 2:4 – At the time of the census: "Joseph also went from the town of Nazareth in Galilee to Judea, to the city of David called Bethlehem, because he was descended from the house and family of David."
Luke 2:16 – When the shepherds visit Bethlehem: "So they went with haste and found Mary and Joseph, and the child lying in the manger."
Luke 2:33 – In reaction to Simeon's words in the Jerusalem Temple: "And the child's father and mother were amazed at what was being said about him."
Luke 2:48-49 – Upon finding Jesus in the Temple, at 12 years old: "When his parents saw him they were astonished; and his mother said to him, "Child, why have you treated us like this? Look, your father and Ihave been searching for you in great anxiety." / He said to them, "Why were you searching for me? Did you not know that I must be in my Father's house?"
Luke 3:23 – In the genealogy of Jesus: "Jesus was about thirty years old when he began his work. He was the son (as was thought) of Joseph son of Heli,"
Luke 4:22 – All spoke well of him and were amazed at the gracious words that came from his mouth. They said, "Is not this Joseph's son?"
Joseph is mentioned only once in the Fourth Gospel:
John 6:42 – In the Bread of Life discourse, some "Jews" object to Jesus' words, saying, "Is not this Jesus, the son of Joseph, whose father and mother we know? How can he now say, 'I have come down from heaven'?"
Other NT Writings:
Joseph of Nazareth is never mentioned in the rest of the New Testament.
Liturgical Celebrations of Joseph:
March 19 – Solemnity of St. Joseph, Husband of the Blessed Virgin Mary
May 1 – Optional Memorial of St. Joseph the Worker
Pope Francis declared a "Year of St. Joseph," celebrated from Dec. 8, 2020, to Dec, 8, 2021.
See the Apostolic Letter, Patris Corde.
Mary of Nazareth:
Letters of St. Paul:
Paul never mentions the mother of Jesus by name, and only once indirectly refers to his human mother.
Gal 4:4-5 – "But when the fullness of time had come, God sent his Son, born of a woman, born under the law, / in order to redeem those who were under the law, so that we might receive adoption as children."
Caution: Paul on one occasion conveys greetings to a different "Mary," someone "who has worked very hard among you" (Romans 16:6).
Gospel acc. to Mark:
The family of Jesus (incl. Mary) is mentioned in only a few passages of Mark, and even in a somewhat negative light.
Mary is explicitly named only once, when people in Jesus' hometown challenge him: "Is not this the carpenter, the son of Mary...?" (Mark 6:3a; par. Matt 13:55)
"His mother" is mentioned earlier (along with his brothers and sisters), when the narrator tells us how the members of Jesus' family were concerned about him:
"When his family (Gk. hoi par' autou) heard it, they went out to restrain him, for people were saying, 'He has gone out of his mind.' " (only in Mark 3:21)
"Then his mother and his brothers came; and standing outside, they sent to him and called him. / A crowd was sitting around him; and they said to him, 'Your mother and your brothers and sisters are outside, asking for you.' / And he replied, 'Who are my mother and my brothers?' / And looking at those who sat around him, he said, 'Here are my mother and my brothers! / Whoever does the will of God is my brother and sister and mother.' " (Mark 3:31-35; par. Matt 12:46-50; Luke 8:19-21)
Some scholars suggest that, in the accounts of Jesus' crucifixion, burial, and resurrection, "Mary the mother of James the younger and of Joses" (Mark 15:40), "Mary the mother of Joses" (15:47), and "Mary the mother of James" (16:1), might also be references to Jesus' mother. However, this interpretation is disputed; these texts more likely refer to another close relative of Mary of Nazareth.
Gospel acc. to Matthew:
Mary is mentioned a little more often in Matthew, in contrast to Mark, but she still does not play a very significant roll.
Matt 1:16 – Mary is first named at the end of Matthew's genealogy: "and Jacob the father of Joseph the husband of Mary, of whom Jesus was born, who is called the Messiah."
Matt 1:18 – Mary's engagement to Joseph and her unexpected pregnancy are mentioned by the evangelist: "Now the birth of Jesus the Messiah took place in this way. When his mother Mary had been engaged to Joseph, but before they lived together, she was found to be with child from the Holy Spirit."
Matt 1:20-21 – An angel speaks about Mary in Joseph's dreams: "Joseph, son of David, do not be afraid to take Mary as your wife, for the child conceived in her is from the Holy Spirit. / She will bear a son, and you are to name him Jesus, for he will save his people from their sins."
Matt 2:11a – Mary is present when the Magi visit in Bethlehem: "On entering the house, they saw the child with Mary his mother; and they knelt down and paid him homage...."
Matt 2:13-14, 20-21 – In later dreams, Joseph is told to "take the child and his mother" and flee to Egypt, and later again to "take the child and his mother" and return to Israel.
Matt 12:46-50 – As in Mark 3:31-35, Jesus' mother and siblings also come to see him while he is teaching crowds of people.
Matt 13:55a – As in Mark 6:3, Mary is also mentioned briefly when the people of Nazareth question how Jesus can be a prophet: "Is not this the carpenter's son? Is not his mother called Mary?"
As in Mark 15 & 16, references to "Mary the mother of James and Joseph" (Matt 27:56) and "the other Mary" (27:61; 28:1) probably do not refer to the mother of Jesus, but to another close relative of hers.
Gospel acc. to Luke:
Mary is much more prominent in Luke than in any of the other Gospels, especially in the Lukan Infancy Narrative.
Luke 1:26-38 – The Annunciation by the Angel Gabriel to Mary
Luke 1:39-56 – The Visitation of Mary to her cousin Elizabeth
Luke 2:1-7 – The Journey to Bethlehem and the Birth of Jesus
Luke 2:8-20 – The Visit of the Shepherds to the Manger in Bethlehem
Luke 2:22-40 – The Purification of Mary and Presentation of Jesus in the Temple
Luke 2:41-52 – The Visit to the Jerusalem Temple when Jesus is 12 years old
Luke 8:19-21 (parallel text to Mark 3:31-35) – "Then his mother and his brothers came to him, but they could not reach him because of the crowd. / And he was told, "Your mother and your brothers are standing outside, wanting to see you." / But he said to them, "My mother and my brothers are those who hear the word of God and do it."
When Jesus visits Nazareth in Luke 4:16-30, there is no mention of Jesus' mother (contrast Mark 6:3a and Matt 13:55a); the townsfolk merely ask, "Is not this Joseph's son?" (Luke 4:22b).
Luke's Gospel later mentions several other Marys, not to be confused with the mother of Jesus, including Mary Magdalene (Luke 8:2; 24:10; cf. 23:55; 24:1-9, 22-24), Mary of Bethany (10:38-42), and Mary the mother of James (24:10).
Acts of the Apostles:
Mary is mentioned only once, near the beginning of the book of Acts.
Acts 1:14 – After naming the eleven apostles who remained in Jerusalem after the Ascension of Jesus, the narrator adds, "All these were constantly devoting themselves to prayer, together with certain women, including Mary the mother of Jesus, as well as his brothers."
Caution: Acts later mentions a different Mary as the mother of John a.k.a. Mark (Acts 12:12).
Gospel acc. to John:
Surprisingly, Mary of Nazareth is never mentioned by name in the Fourth Gospel, but is simply called "the mother of Jesus" and/or addressed as "Woman" in the two episodes, in which she has very prominent roles.
John 2:1-11 – The Wedding at Cana:
"On the third day there was a wedding in Cana of Galilee, and the mother of Jesus was there. / Jesus and his disciples had also been invited to the wedding. / When the wine gave out, the mother of Jesus said to him, 'They have no wine.' / And Jesus said to her, 'Woman, what concern is that to you and to me? My hour has not yet come.' / His mother said to the servants, 'Do whatever he tells you.' " (2:1-5)
John 2:12 – The evangelist concludes the Cana story with a geographical transition: "After this he went down to Capernaum with his mother, his brothers, and his disciples; and they remained there a few days."
John 6:42 – Later, the Jewish authorities challenge Jesus, saying: "Is not this Jesus, the son of Joseph, whose father and mother we know? How can he now say, 'I have come down from heaven'?"
John 19:25b-27 – The Crucifixion of Jesus:
"Meanwhile, standing near the cross of Jesus were his mother, and his mother's sister, Mary the wife of Clopas, and Mary Magdalene. / When Jesus saw his mother and the disciple whom he loved standing beside her, he said to his mother, 'Woman, here is your son.' / Then he said to the disciple, 'Here is your mother.' And from that hour the disciple took her into his own home."
The Fourth Gospel includes several other women named "Mary," including Mary of Bethany (John 11; 12:3), Mary Magdalene (19:25; 20:1-18), and Mary the wife of Clopas (19:25); but these are not to be confused with the mother of Jesus.
Book of Revelation:
The story of the woman and the dragon (Rev 12:1-6) is often interpreted as involving Mary, the mother of Jesus.
"A great portent appeared in heaven: a woman clothed with the sun, with the moon under her feet, and on her head a crown of twelve stars. / She was pregnant and was crying out in birthpangs, in the agony of giving birth. / Then another portent appeared in heaven: a great red dragon, with seven heads and ten horns, and seven diadems on his heads. / His tail swept down a third of the stars of heaven and threw them to the earth. Then the dragon stood before the woman who was about to bear a child, so that he might devour her child as soon as it was born. / And she gave birth to a son, a male child, who is to rule all the nations with a rod of iron. But her child was snatched away and taken to God and to his throne; / and the woman fled into the wilderness, where she has a place prepared by God, so that there she can be nourished for one thousand two hundred sixty days."
Most biblical scholars, however, suggest that this story originally referred more generally to the nation of Israel bringing forth the Messiah, and was only later reinterpreted as referring more specifically to Mary and Jesus.
Roman Catholic Teachings about Mary:
Lumen Gentium (Second Vatican Council: "Dogmatic Constitution on the Church"):
Chapter 8: "The Role of the Blessed Virgin Mary, Mother of God, in the Mystery of Christ and the Church" (par. 52-69)
Part One, Section Two, Chapter Two, Article 3, Paragraph 2: "Conceived by the Power of the Holy Spirit and Born of the Virgin Mary" (par. 484-511)
Part One, Section Two, Chapter Three, Article 8, IV: "Rejoice, you who are full of grace" (par. 721-726)
Part One, Section Two, Chapter Three, Article 9, Paragraph 6: "Mary—Mother of Christ, Mother of the Church" (par. 963-975)
Papal Bulls and Encyclicals:
Pope Pius IX: Ineffabilis Deus(Dec. 8, 1854) - proclaimed the Immaculate Conception of the Blessed Virgin Mary as an infallible dogma; celebrated annually on Dec. 8
Pope Pius XII: Munificentissimus Deus (Nov. 1, 1950) - proclaimed the Assumption of the Blessed Virgin Mary as an infallible dogma; celebrated annually on Aug. 15
Pope Pius XII: Ad Caeli Reginam (Oct. 11, 1954) - established the feast of the Queenship of Mary; celebrated annually on Aug. 22
Pope John Paul II: Redemptoris Mater (March 25, 1987) - the most recent Encyclical to focus on the Blessed Virgin Mary
Jan. 1 - Blessed Virgin Mary, Mother of God (Solemnity)
also called Theotokos (lit. "God-bearer") – as defined by the Council of Ephesus (AD 431)
Feb. 2 - Presentation of the Lord (Feast)
Feb. 11 - Our Lady of Lourdes (optional Memorial)
March 25 - Annunciation of the Lord (Solemnity)
May 13 - Our Lady of Fatima (optional Memorial)
May 31 - Visitation of the Blessed Virgin Mary (Feast)
Monday after Pentecost - Blessed Virgin Mary, Mother of the Church (Memorial)
Sat. after 2nd Sun. after Pentecost - The Immaculate Heart of the Blessed Virgin Mary (optional Memorial)
July 5 - Our Lady of Refuge: Patroness of the Californias (Proper in California)
July 16 - Our Lady of Mount Carmel (optional Memorial)
July 26 - Sts. Joachim and Anne, parents of the Blessed Virgin Mary (Memorial)
Aug. 5 - The Dedication of the Basilica of St. Mary Major in Rome (optional Memorial)
Aug. 15 - Assumption of the Blessed Virgin Mary (Vigil & Day: Solemnity)
sometimes also called Mary's Death or Dormition or Transition into Heaven
Aug. 22 - The Queenship of the Blessed Virgin Mary (Memorial)
Sept. 8 - Nativity of the Blessed Virgin Mary (Feast)
Sept. 12 - The Most Holy Name of the Blessed Virgin Mary (optional Memorial)
Sept. 15 - Our Lady of Sorrows (Memorial; aka Our Mother of Sorrows)
Oct. 7 - Our Lady of the Rosary (Memorial)
Nov. 21 - The Presentation of the Blessed Virgin Mary (Memorial)
Dec. 8 - Immaculate Conception of the Blessed Virgin Mary (Solemnity)
Dec. 12 - Our Lady of Guadalupe (Feast in USA)
Other Post-Biblical Doctrines about Mary:
Mary's Childhood & her Marriage to Joseph – Various episodes are mentioned in the Proto-Evangelium of James and other non-canonical Gospels.
Perpetual Virginity of Mary – The belief that Mary had no other children after Jesus; a belief accepted by most Orthodox and Catholic Christians, but only few Protestant Christians.
The Brothers and Sisters of Jesus:
Several passages of the four canonical Gospels mention "brothers" and/or "sisters" of Jesus.
Four "brothers" are explicitly named in the Gospels, while the "sisters" of Jesus remain anonymous.
Mark 3:21 – When his family heard it, they went out to restrain him, for people were saying, "He has gone out of his mind."
Mark 3:31-35 – Then his mother and his brothers came; and standing outside, they sent to him and called him. 32 A crowd was sitting around him; and they said to him, "Your mother and your brothers and sisters are outside, asking for you." 33 And he replied, "Who are my mother and my brothers?" 34 And looking at those who sat around him, he said, "Here are my mother and my brothers! 35 Whoever does the will of God is my brother and sister and mother." (parallel texts in Matt 12:46-50; Luke 8:19-21)
Mark 6:2-3 – On the sabbath he began to teach in the synagogue, and many who heard him were astounded. They said, "Where did this man get all this? What is this wisdom that has been given to him? What deeds of power are being done by his hands! / 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.
Matt 12:46-50 – parallel text to Mark 3:31-35
Matt 13:54-56 – He came to his hometown and began to teach the people in their synagogue, so that they were astounded and said, "Where did this man get this wisdom and these deeds of power? 55 Is not this the carpenter's son? Is not his mother called Mary? And are not his brothers James and Joseph and Simon and Judas? 56 And are not all his sisters with us? Where then did this man get all this?"
Luke 8:19-21 – parallel text to Mark 3:31-35
John 2:12 – After this [the wedding at Cana] he went down to Capernaum with his mother, his brothers, and his disciples; and they remained there a few days.
John 7:2-10 – Now the Jewish festival of Booths was near. 3 So his brothers said to him, "Leave here and go to Judea so that your disciples also may see the works you are doing; 4 for no one who wants to be widely known acts in secret. If you do these things, show yourself to the world." 5 (For not even his brothers believed in him.) 6 Jesus said to them, "My time has not yet come, but your time is always here. 7 The world cannot hate you, but it hates me because I testify against it that its works are evil. 8 Go to the festival yourselves. I am not going to this festival, for my time has not yet fully come." 9 After saying this, he remained in Galilee. 10 But after his brothers had gone to the festival, then he also went, not publicly but as it were in secret.
John 20:17-18 – Jesus said to her [Mary Magdalene], "Do not hold on to me, because I have not yet ascended to the Father. But go to my brothers and say to them, 'I am ascending to my Father and your Father, to my God and your God.'" / Mary Magdalene went and announced to the disciples, "I have seen the Lord"; and she told them that he had said these things to her.
Acts 1:14 – [After naming the eleven apostles]: All these were constantly devoting themselves to prayer, together with certain women, including Mary the mother of Jesus, as well as his brothers.
Gal 1:18-19 – [Paul recounts his early Christian life]: "Then after three years I did go up to Jerusalem to visit Cephas and stayed with him fifteen days; / but I did not see any other apostle except James the Lord's brother."
1 Cor 9:5 – [Paul asks the Corinthians]: "Do we not have the right to be accompanied by a believing wife, as do the other apostles and the brothers of the Lord and Cephas?"
How closely are these "brothers and sisters" related to Jesus and to Mary? The exact relationships have been disputed throughout Christian history, because the Greek words adelphoi and adelphai can refer not only to the children of someone's own mother and father, but also to other close relatives in an extended family or clan, or sometimes even more broadly to people with no blood-relationship at all.
Full-brothers and sisters – children of the same mother and father; closest possible blood-relatives
Half-brothers and sisters – children of the same mother but with a different father, or vice-versa
Step-brothers and sisters – children who become related only due to later marriages of one of their parents
Brothers and sisters-in-law – adults who become legally related through the marriage of a sibling
Adopted brothers and sisters – children of other parents who legally become family members and co-heirs
Cousins in extended families – children of people who are closely related to one's own parents
Metaphorical brothers and sisters – members of "fictive kinship" groups (such as modern "fraternity brothers" and "sorority sisters")
Different Christian Churches and denominations have different traditions of interpretation on the question regarding who the "brothers and sisters" of Jesus were:
Most Protestant Christians – full siblings; younger children of both Mary and Joseph
Eastern Orthodox Christians – half-siblings; older children of Joseph, a widower, from a previous marriage
Roman Catholic Christians – cousins; children of close relatives of Mary and/or Joseph
Which of these three options is historically most accurate cannot be determined from the biblical evidence alone; the answer relies on the post-biblical traditions of interpretation.
Doesn't Matthew 1:25 imply that Mary and Joseph had more children?
No, because the Greek preposition ἕως / heōs, often translated "until," is only talking about the time period before or up to some event, without necessarily implying what happened later.
Greek ἕως / heōs is used 146 times in the NT, including 49 times in the Gospel according to Matthew.
The NRSV of Matthew translates the preposition as "until" 25 times, but also uses "to" (12x), "while" (3x), "before" (2x), "as far as" (2x), and several other phrases (5x).
The reference is to something before a particular point in time; in some cases a change takes place after that point in time, but in other cases the same thing continues afterward.
Matt 1:24-25 - "When Joseph awoke from sleep, he did as the angel of the Lord commanded him; he took her as his wife, / but had no marital relations with her until she had borne a son; and he named him Jesus." (NRSV)
Here, the phrase "until she had borne a son" simply means "up until the time when she had borne a son"; but it does not state whether the same thing ("he had no marital relations with her") continued or changed after Mary gave birth to Jesus. Matthew's concern is simply to emphasize that Jesus could not be the physical child of Joseph, since he and Mary had no marital relations before Jesus' birth; but this statement does not say whether or not they had sexual relations later, possibly producing more children.
Some modern analogies might help to explain this difference:
Saying "I didn't drink anything until I was in college" seems to imply that I did drink while going to college.
Using the preposition "before" doesn't change the meaning very much: "I didn't drink anything before I was in college" also seems to imply that I did drink during college.
But saying "I didn't drink anything before the car crash" (i.e. up until the time of the crash) does not imply that I drank anything after the crash. That may or may not be true, but doesn't following immediately from the earlier statement.
Some examples of ἕως / heōs used in Matthew's Gospel clearly imply a change from before to after: "stay there until you leave" (Matt 10:11).
But other uses of ἕως / heōs do not necessarily imply a change after the referenced point in time:
Matt 16:28 - "Amen, I say to you, there are some standing here who will not taste death until (Gk. heōs) they see the Son of Man coming in his kingdom" (NAB). - This does not necessarily mean that they "will taste death" after the Son of Man comes. So saying "will not taste death before they see the Son of Man..." (NRSV) might be a slightly better English translation.
Matt 22:44 - 'The Lord said to my Lord, "Sit at my right hand, until I put your enemies under your feet" '? - This does not imply that the Lord may not remain seated after the enemies are subdued.
Matt 24:39 - "and they knew nothing until the flood came and swept them all away, so too will be the coming of the Son of Man." - Clearly this does not imply that the people did know something more after they had died!
Matt
27:8 - "For this reason that field has been called the Field of Blood to (Gk. heōs) this day" (NRSV). - This is clearly not claiming that there was a change (that the field was given a different name) soon after the Evangelist wrote this verse!
Matt 28:20b - "And remember, I am with you always, to (Gk. heōs) the end of the age." - Does this imply that Jesus will not continue to be with the disciples after "the end of the age"? No, it clearly means Jesus is with us always, both before and after the end of the present age!
