Some protestants and other non-christians claim that Mary had other children and that she did not remain an ever virgin as the Catholic Church teaches.  This belief is not scriptural nor is it historically correct.  The Catholic Church teaches and has always taught that Mary was an ever virgin.

*Question: The Bible clearly says that Jesus had brothers and sisters, but the Catholic Church teaches that Mary was a perpetual virgin...how can you reconcile those seemingly different positions?

*Answer: Mark 6:3 says, "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?" We need to realize a few things here about these "brothers and sisters". First, there was no word for cousin,, nephew, niece, aunt or uncle in ancient Hebrew or Aramaic.  The words that the Jews used in all those instances were "brother" or "sister".  An example of this can be seen in Gen 14:14, where Lot, who was Abraham's nephew, is called his brother. Also, we see from Mt. 27:55-56, that the James and Joses mentioned in Mark 6 as the "brothers" of Jesus, are actually the sons of another Mary.

 

Another passage to consider is Acts 1:14-15, "[The Apostles] with one accord devoted themselves to prayer, together with the women and Mary the mother of Jesus and with His brothers...the company of persons was in all about a hundred and twenty." A company of 120 persons composed of the Apostles, Mary, the women, and the "brothers" of Jesus.

 

Let's see there were 11 Apostles at the time. Jesus' mother makes 12. The women, probably the same three women mentioned in Matthew 27, but let's say it was maybe a dozen or two, just for argument's sake. So that puts us up to 30 or 40 or so. So that leaves the number of Jesus' brothers at about 80 or 90! Do you think Mary had 80 or 90 children? She would have been in perpetual labor! No, Scripture does not contradict the teaching of the Catholic Church about the "brothers" of Jesus, when Scripture is properly interpreted in context.  

 

*(Taken from the following Website:  http://www.biblechristiansociety.com/  By: John Martinoni)

Bible verses that back up the Catholic Church's claim that Mary was an ever virgin and had no other children besides Jesus:

“And stretching out his hand toward his disciples, he said, "Here are my mother and my brothers! For whoever does the will of my Father in heaven is my brother, and sister, and mother.”  (Matt 12:49-50)

“Then he appeared to more than five hundred brethren at one time, most of whom are still alive, though some have fallen asleep.”  (1Cor 15:6)  Jesus appeared to 500 brethren or brothers.  If you are going to accept the interpretation of “brothers” as meaning a sibling in other places in the bible then you have to accept that same interpretation here.  500 literal brothers - Impossible!

“Now these are the descendants of Terah. Terah was the father of Abram, Nahor, and Haran; and Haran was the father of Lot.” (Gen 11:27)”  However in Gen 14:14 ... Lot,  is called Abraham's brother.

Gen 29:15 ... Laban, Jacob's uncle, calls Jacob his "brother" (KJV).

“He (Joseph) had no relations with her until (heos) she bore a son, and he named him Jesus.” (Mt 1:25)  The Greek and the Semitic use of the word heos (until or before) does not imply anything about what happens after the time indicated.   In this case, there is no necessary implication that Joseph and Mary had sexual contact or other children after Jesus.  Again, in order to come to the correct meaning of this verse we must fully understand the Greek language in which the original texts were written in.

“Jesus said to her, "Do not hold me, for I have not yet ascended to the Father; but go to my brethren and say to them, I am ascending to my Father and your Father, to my God and your God."  Mary Magdalene went and said to the disciples, "I have seen the Lord"; and she told them that he had said these things to her.  (John 20: 17-18)  What brothers did Mary go to?  If brethren here meant blood brothers then Mary disobeyed Jesus’s command by going to see the disciples.  Brethren here obviously meant disciples and not
actual blood bothers.

“And behold, Jesus met them and said, "Hail!" And they came up and took hold of his feet and worshiped him. Then Jesus said to them, "Do not be afraid; go and tell my brethren to go to Galilee, and there they will see me.” (Matt 28:9-10)  Jesus is referring to his disciples here, but yet he call them his brethren or brothers.

You have to keep your Mary’s straight.........................
“Is not this the carpenter (Jesus), 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.” (Mk 6:3).  See Jesus had brothers right?  Wrong!  James here is the son of Clophas (Alpaneus), not Jospeh!   See the passages listed below.  

“ And he (Jesus)  appointed twelve, to be with him, and to be sent out to preach and have authority to cast out demons: Simon whom he surnamed Peter; James the son of Zeb'edee and John the brother of James, whom he surnamed Bo-aner'ges, that is, sons of thunder; Andrew, and Philip, and Bartholomew, and Matthew, and Thomas, and James the son of Alphaeus (Clophas), and Thaddaeus, and Simon the Cananaean, and Judas Iscariot, who betrayed him.”  (Mark 4:14-19)  If either James here is the blood brother of Jesus and son of Mary then James should be the son of Jospeh in this passage.  

“So the soldiers did this. But standing by the cross of Jesus were his mother, and his mother's sister, Mary the wife of Clophas (Alphaeus), and Mary Magdalene. When Jesus saw his mother, and the disciple whom he loved standing near, he said to his mother, "Woman, behold, your son!”  (John 19:25)

“ Then he said to the disciple, "Behold, your mother!" And from that hour the disciple took her to his own home.John “  (19:26-27)   Jesus gives care of Mary to John, not one of his "brothers."  This would have gone against Jewish tradition and greatly  offended his “brother” James.  It was Jewish custom for the oldest son to care for his mother.  

“among whom were Mary Magdalene, and Mary the mother of James and Joseph, and the mother of the sons of Zebedee.”  (Matt 27:56)

There were also women looking on from afar, among whom were Mary Magdalene, and Mary the mother of James the younger and of Joseph, and Salome,  (Mk 15:40)

“Mary Magdalene and Mary the mother of Joseph saw where he was laid.” (Mk15:47) The second Mary is not the Virgin Mary, but Mary the wife of Clophas (Alphaeus) so this does not prove that Mary had other children.

Genealogy of James, John, and Jesus:
Zebedee & Salome begat - James and John (Mt 4:21,Mk 1:19, Mk 3:17, Mt 27:56, Mk 15:40)

Cleophas (Alphaeus) & Mary (the other Mary) begat - James (the less), Joseph (Joses), and Jude (Mt 10:2-3,
Jn 19:25, Acts 1:13,  Mt 27:56,61, 28:1, John 19:25)

THE HOLY SPIRIT (Luke 1:35-38) – begat JESUS THE CHRIST through the Virgin Mary (Lk 1:30-38)

One last thing to consider:  If there were blood brothers and sisters of Jesus that would mean that somewhere on earth today there should be a descendant of Mary & Joseph and hence a “Jesus” bloodline.  If this were true this bloodline surely would have revealed at sometime during history.