Question: Why do Catholics believe Mary had no other children?
Nowhere in Scripture does it say that Mary had other children. Scripture speaks of Jesus as "the son of Mary" [Mk 6:3], and not "a son of Mary," and the Greek expression used here does imply that Jesus is Mary's only son.
Scripture also speaks of the "brothers of the Lord," but they are never called "sons" of Mary.
The testimony of the early Church is virtually unanimous on this, and the doctrine of Mary's perpetual virginity went without significant challenge for the first 4 centuries of Christianity.
For example, in 360, St. Athanasius, the great defender of the Trinity, wrote, "Let those who deny that the Son is from the Father ... deny also that He took true human flesh of Mary ever-virgin."
Around 380 St. Jerome, one of the greatest Scripture scholars in history, responded to a theologian named Helvidius that his idea of Mary having other children was "novel, wicked, and a daring affront to the faith of the whole world."
Citing Scripture and Christian writers such as Sts. Ignatius, Polycarp, Irenaeus, Justin Martyr, and more, he penned his famous treatise, "On the Perpetual Virginity of the Blessed Mary," stating, "You say that Mary did not continue a virgin: I claim still more that Joseph himself, on account of Mary, was a virgin, so that from a virgin wedlock a virgin son was born."
Helvidius's theory quickly fell into disrepute.
Shocking to some, the Protestant reformers were equally unanimous in their belief in Mary's perpetual virginity. Martin Luther declared, "It is an article of faith that Mary is Mother of the Lord and still a virgin."
Ulrich Zwingli was equally adamant: "I esteem immensely the Mother of God, the ever chaste, immaculate Virgin Mary." John Wesley wrote that Jesus was "born of the blessed Virgin Mary, who, as well after as before she brought Him forth, continued a pure and unspotted virgin."
So virtually all of Christianity for well over 1,500 years held the view that Mary was perpetually virgin. You have to wonder how this novel idea of Mary having other children has resurfaced. It rests predominantly in several misinterpretations of certain Scripture passages.
Scripture supports the doctrine of perpetual virginity. In Lk 1:34, the angel Gabriel tells the now betrothed Mary (cf Mt 1:18) that she will bear a son. Now this would be an absolutely normal thing to say to someone who was betrothed, essentially married according to Jewish Law. Of course a young bride would be hoping and expecting to bear children.
But Mary replies, "How shall this be, since I know not man?" This question to the angel makes no sense unless Mary already has some sort of an intention or vow of virginity, with no intention of having relations with a man.
The angel answers, 'The holy Spirit will come upon you, and the power of the Most High will overshadow you'" (Lk 1:34-35). To "overshadow" a woman was a Biblical euphemism for having a marital relationship.
After Mary agrees to this proposal, in a spiritual sense, she becomes the spouse of the Holy Spirit, and from that point, it would be unfitting for another to have relations with her.
In fact, St. Joseph would in a sense be required by Mosaic Law to divorce Mary, because she would then be joined to another (see Dt 24:1-4, Jer 3:1). He might feel this even more keenly knowing that the "other" was the Holy Spirit!
Who could possibly be worthy to even wed such a woman, a woman chosen by God Himself to bear His Son; never mind have marital relations with her. But obedient to the Holy Spirit, he takes Mary and Jesus into his home.
Consider Uzzah, struck dead for simply touching the Ark of the Covenant (2 Sam. 6:6-8). How much more would Joseph understand the holiness of Mary, the New Ark carrying the Word-made-Flesh, and that she, even more so, had been set apart for God alone.
Now some contend that, on these grounds, Mary and Joseph would not have even been truly married, because their marriage would have been invalid because it was not consummated. But a marriage still occurs with the exchange of vows (which had already occurred between Mary and Joseph at their betrothal), whether consummated or not, but it becomes indissoluble when consummated, because the two have now become one flesh.
Many object, citing the apparent "brothers" or "sisters of the Lord," mentioned in Gal 1:19, Mt 13,:55 and other places. But a careful study of these verses reveals some very interesting things which will be the focus of my next column.