For a start, both Joseph (Matt.13:55) and Jesus (Mark 6:3) were carpenters. It is the eldest son who gets trained in his father's occupation; the others have to be apprenticed elsewhere. If, perchance, the eldest finds another skill more congenial, then it devolves ton o the second. But it doesn't go all the way down to the baby of the family.
Also, look at the incident in the temple described in Luke 2:41-51. Here the twelve year old Jesus, as a free range kid, got so caught up in the theological discussions that he missed the department of the caravan heading back to Nazareth. The point is this is far more likely to have happened if Mary and Joseph had their hands full with a bunch of younger children than if there were a large number of older stepbrothers, some probably adults or approaching adulthood, looking out for Him.
Apart from that, where were these older children when Jesus was born. Did they come down to Bethlehem with their father? Did they go to Egypt as well? Why are they never mentioned until the time of Jesus' ministry?
It must be emphasized that this hypothetical first marriage of Joseph has been brought into the picture solely in order to satisfy a pre-conceived belief that Mary was a perpetual virgin. But there is no documentary evidence for it anywhere. The Protoevangelium of James does not count because it is a recognized work of fiction.
Nevertheless, since the Protoevangelium was the document which introduced the concept, we should remind ourselves of its narrative. According to it, Mary was sent to the temple at the age of three, where she was fed by an angel. When the elders got worried about the approach of her first period, the angel told them to offload her onto a pious widower. This is not only fictional, but fantastic. We should therefore ignore the story and instead factor in human nature and practicalities.
Marriages in those days were semi-arranged. Finding a marriage partner was the task of both parents and their child, with consent being required from both parties. But under normal circumstances, a young woman will consent to marrying a much older man, especially one with dependents, and her parents even consider it, if he can provide much greater economic security than someone her own age. Joseph did not fit the bill. At her ritual of purification, they had to resort to the “offering of the poor” of two doves, because they could not afford a lamb (Luke 2: 24). No, Joseph was not an old man. The fact that he apparently died before Jesus was thirty does not negate that. Death in the prime of life was very common. After all, Anna was widowed after only seven years of marriage (Luke 2:36-37). The same was true in our own society under very recently. These days, when it happens, we ask, "What went wrong?", but up to a few generations ago it was taken for granted that anyone who survived to a ripe old age had beaten the odds.
Based on the customs of the time, we must picture Mary as being about fifteen or sixteen, and Joseph no more than twenty. On the shoulders of these two young people were thrust the most awesome responsibility of their time. Fortunately, by the grace of God, they were up to it.
Nevertheless, the stepsibling scenario was the favoured explanation for those who believed in the perpetual virginity of Mary - until a man called St. Jerome came along. We will examine this in Part 4.
