Scripture tells us practically nothing about the first years and the boyhood of the Child Jesus. All we know are the facts of the sojourn in Egypt, the return to Nazareth, and the incidents that occurred when the twelve-year-old boy accompanied his parents to Jerusalem. In her liturgy the Church hurries over this period of Christ’s life with equal brevity.
The general breakdown of the family, however, at the end of the past century and at the beginning of our own, prompted the popes, especially the far-sighted Leo XIII, to promote the observance of this feast with the hope that it might instill into Christian families something of the faithful love and the devoted attachment that characterize the family of Nazareth.
The primary purpose of the Church in instituting and promoting this feast is to present the Holy Family as the model and exemplar of all Christian families.
(catholicculture.org, 2019, excerpted from With Christ Through the Year, Rev. Bernard Strasser, O.S.B.)