Jesus was a real human being and grew up as an ordinary child. In fact, it was his very ordinariness that scandalized his neighbors and prevented them from allowing him to be their Messiah and Savior.
Mark quotes the people in the synagogue of Nazareth asking the question: “Is he not the carpenter, the son of Mary, and the brother of James and Joses and Judas and Simon? And are not his sisters here with us?” The question is how does this square with the Catholic doctrine of the Virgin Birth and more particularly the doctrine of the Perpetual Virginity of Mary?
Historically there are three positions that have been taken:
1) These were the natural children of Mary and Joseph. This is the position adopted by many Protestant scholars.
2) These were the children of Joseph by an earlier marriage and so they are Jesus’ stepbrothers and sisters. This was the position held by most Christians in the first four centuries and by the Orthodox Church.
3) These were the cousins of Jesus, perhaps the sons and daughters of Mary’s sister. This view asserts that the word brethren has a looser meaning than we use today and there are many references in the Old Testament which can be brought forward to support this.
This is the position most frequently taken by the Roman Catholic Church. While there are several references to Jesus’ brothers, including this one, there is no single reference in the New Testament to Mary’s sons. In addition in that time there wasn’t a last name, after the name people usually said son of and father’s name, but here people of Nazareth said the son of Mary, and they do not say, one of Mary’s sons. But perhaps the most important scriptural argument is this: from the Cross Jesus put his mother under the protection of the loved disciple, and he made a place for her in his home. How would this possible if Jesus had more brothers and sisters?