Ever since I worked in a Jesuit parish in a slum in Nairobi, Kenya called Mtakatifu Yosefu Mfanyakazi, or St. Joseph the Worker, I have been drawn to this aspect of the foster father of Jesus. Of course we know little about him, other than the little that the Gospels tell us. Joseph is given no lines to speak at all in the Gospels. Yet his "work" though hidden, was important.
His "hidden life" was a time spent caring for his son—-or to put it more precisely, his "foster son"—-and teaching him the trade of carpentry. (The Greek word used in the Gospels of Mark and Matthew is tekton, which can be variously translated as "craftsman" or "woodworker," but is traditionally rendered as "carpenter.") In Joseph's workshop in Nazareth, Jesus would have learned about the raw materials for his craft: which wood was best suited for chairs and tables, which worked best for yokes, for ploughs. An experienced Joseph would have taught his apprentice the right way to drive a nail with a hammer, the proper way to drill a clean and deep hole in a plank, the correct way to level a ledge or lintel.
Undoubtedly, Joseph would have passed on to Jesus the values required to become a good carpenter. You need patience (for waiting until the olive wood is dry and ready), judgement (for ensuring that your plumb line is straight), honesty (for charging people a fair price) and persistence (for sanding until the tabletop is smooth to the touch). Alongside his teacher, a young Jesus labored and built, contributing all the while to the common good of Nazareth and the surrounding towns. And is it too difficult to imagine that the skills Jesus learned from his teacher-—patience, judgement, honesty and persistence—would serve him well in his later ministry? Joseph helped to fashion Jesus into what the theologian John Haughey, S.J., called "the instrument most needed for the salvation of the world."
As a father, Joseph would have been one of his son's primary teachers in his religious faith as well. Introducing him to the great men and women of the Scriptures, teaching him the Hebrew prayers, preparing him for his bar mitzvah, encouraging his boy to listen to the rabbis and religious leaders of the town. And talking to him about God. Children and adolescents are usually bursting with questions about God. It is probable that Joseph was the first one who Jesus went to with his questions. So Jesus's understanding of God the Father, his Father, may have been shaped not only by Joseph's own life, but by Joseph's answers to his questions. Joseph's faith was one of the foundations of Jesus's faith.
James Martin, SJ
Also, here's a little video about St. Joseph the Worker and his hidden life, from the DVD "Who Cares about the Saints?"