Since the early eras of Christianity, the Holy Catholic Church has been questioned by the heretics on her doctrine concerning the perpetual virginity of the Blessed Virgin Mary as they insisted that the latter had other children after Jesus making them as His siblings, citing the Gospels of Mark 6:3 and Matthew 13:55-56 which state that James, Joses (or Joseph), Judas, and Simon were the brothers of Jesus, together with an unnamed sisters. However, did the Lord really have siblings? Did Mary really have other children after Jesus?
The controversy exists in clearly understanding the meaning of the word brother. In the original text of the Gospels, the Greek word adelphos, meaning brothers, is used. However, adelphos does not solely mean blood brothers born of the same parents but was also used to describe brothers not born of the same parents, like a half-brother or step-brother. The word also described other relationships like cousins, nephews, uncles, etc. For instance in Genesis 13:8 and 14:14-16, the same word adelphos was used to describe the relationship between Abraham and Lot who did not share a blood brother relationship, but one of uncle and nephew. Another instance is that of Laban, who was an adelphos to Jacob, not as a brother, but as an uncle. It can also be proven that the word brother used in the New Testament does not intend for a blood brother relatiosnhip alone through the first letter of St. Paul to the Corinthians 15:6 where the apostle wrote that “[Jesus] appeared to more than five hundred . . . brothers at the same time.” Obviously, the Blessed Mother did not give birth to five hundred other children. See?!
Though, according to a second-century Christian writer Hegesippus that there exists a word for cousin in Greek, i.e. anepsios, and is never used of James or the other siblings of Jesus, but it can be noted that Jesus and His disciples’ native language was Aramaic (as in Matthew 27:46; Mark 5:41), which, like Biblical Hebrew, does not contain a word for cousin, nephew or aunt, half-brother, or step-brother; so the word brother or a circumlocution, such as in the case of a cousin, “the son of the brother of my father” was used. Thus, when the Old Testament was translated into Greek and the New Testament written in Greek, the word adelphos was used instead to signify all of these meanings for male relatives. But, who are these so-called brothers of the Lord?
The New Testament writings are clear on this matter. James and Joses (Joseph) were the sons of Mary of Cleophas (cf. Mark 15:40). Mary of Cleophas is described in the Gospel of John as the Blessed Mother’s “sister” (cf. John 20:25); obviously, making James and Joses cousins of the Lord. Judas was the son of James [(not one of the apostles) (cf. Luke 6:16)]. James the Lesser was the son of Alphaeus (cf. Luke 6:15). James the Greater and John were the sons of Zebedee with a mother other than the Blessed Mother Mary (cf. Matthew 20:20ff). Thus, how could they be the blood brothers of Christ the Lord if they were born of different parents?! Simply, logic.
Another proof that the Mother of God had no other children aside from Christ and that Christ had no blood siblings is shown in the crucifixion scene. In the Gospel of John 19:26, before His death on the cross, the Lord says to Mary, “Woman, there is your son,” and then to St. John, who is definitely not a blood brother, “There is your mother.” According to Jewish law and tradition, the eldest son should have the responsibility of caring for the widowed mother, and that responsibility would be passed to the next oldest in the event of the first born son’s inability. By this time, St. Joseph had already died. Obviously, since Jesus had no blood brothers, He entrusted instead His Mother to the care of His beloved disciple. See?!
Nevertheless, though those men were called to be brothers of the Lord, there’s nowhere in the Bible that they were called sons of Mary, the mother of Jesus. The Sacred Scriptures only and explicitly mention “the Son of Mary” who is the Lord Jesus Christ Himself and there are no others.
While the most common Catholic view maintains that the adelphoi were Jesus’ cousins following Papias of Hierapolis (ca. AD 70-163) in his work Exposition of the Sayings of the Lord and the arguments made by St. Jerome (AD 347-420), the Eastern Orthodox argue that they were Joseph’s children by his (unrecorded) first marriage following the most known non-canonical work Proto-evangelium of James (A.D. 125) where Joseph, after being chosen by God to be the protector of Mary, responded: “I have children, and I am an old man, and she is a young girl” (4:9); also from the arguments of Origen (AD 184-254), Eusebius (AD 260/265-339/340), and Epiphanius (ca. AD 310/320-403) to defend the doctrine of perperual virginity of Mary.
However, the Holy Catholic Church only defined a doctrine that they are not biological children of Mary, their exact status, either as cousins or stepbrothers (children of Joseph), is not defined as a doctrine or a dogma either. She infallibly teaches that “Jesus is Mary’s only son, but her spiritual motherhood extends to all men whom indeed he came to save: ‘The Son whom she brought forth is he whom God placed as the first-born among many brethren, that is, the faithful in whose generation and formation she co-operates with a mother’s love'” (CCC 501).