Yea or Nay? Do you believe she remained a virgin her whole life and only Jesus developed in her womb? I was surprised to find out that the three big Reformers Luther, Calvin and Zwingli all believed in this and were actually pretty adament about it.
These are the arguments for it:
IV. Mary is Ever Virgin
Exodus 13:2,12 - Jesus is sometimes referred to as the "first-born" son of Mary. But "first-born" is a common Jewish expression meaning the first child to open the womb. It has nothing to do the mother having future children.
Exodus 34:20 - under the Mosaic law, the "first-born" son had to be sanctified. "First-born" status does not require a "second" born.
Ezek. 44:2 - Ezekiel prophesies that no man shall pass through the gate by which the Lord entered the world. This is a prophecy of Mary's perpetual virginity. Mary remained a virgin before, during and after the birth of Jesus.
Mark 6:3 - Jesus was always referred to as "the" son of Mary, not "a" son of Mary. Also "brothers" could have theoretically been Joseph's children from a former marriage that was dissolved by death. However, it is most likely, perhaps most certainly, that Joseph was a virgin, just as were Jesus and Mary. As such, they embodied the true Holy Family, fully consecrated to God.
Luke 1:31,34 - the angel tells Mary that you "will" conceive (using the future tense). Mary responds by saying, "How shall this be?" Mary's response demonstrates that she had taken a vow of lifelong virginity by having no intention to have relations with a man. If Mary did not take such a vow of lifelong virginity, her question would make no sense at all (for we can assume she knew how a child is conceived). She was a consecrated Temple virgin as was an acceptable custom of the times.
Luke 2:41-51 - in searching for Jesus and finding Him in the temple, there is never any mention of other siblings.
John 7:3-4; Mark 3:21 - we see that younger "brothers" were advising Jesus. But this would have been extremely disrespectful for devout Jews if these were Jesus' biological brothers.
John 19:26-27 - it would have been unthinkable for Jesus to commit the care of his mother to a friend if he had brothers.
John 19:25 - the following verses prove that James and Joseph are Jesus' cousins and not his brothers: Mary the wife of Clopas is the sister of the Virgin Mary.
Matt. 27:61, 28:1 - Matthew even refers to Mary the wife of Clopas as "the other Mary."
Matt. 27:56; Mark 15:47 - Mary the wife of Clopas is the mother of James and Joseph.
Mark 6:3 - James and Joseph are called the "brothers" of Jesus. So James and Joseph are Jesus' cousins.
Matt. 10:3 - James is also called the son of "Alpheus." This does not disprove that James is the son of Clopas. The name Alpheus may be Aramaic for Clopas, or James took a Greek name like Saul (Paul), or Mary remarried a man named Alpheus.