Devotion to the Sacred Heart of Jesus and the Immaculate Heart of Mary is well known in the Catholic world, and is practiced extensively. It can hardly be stressed how important these two devotions are, especially when understood in the broadest sense as speaking of Christic worship and Marian devotion itself.
Joseph as a Member of the Hypostatic-Order
Yet the model of the Holy Trinity on earth consists in three members, not two: Jesus, Mary and Joseph, who together constitute the Holy Family and belong to what has been referred to as the hypostatic-order. A term which describes the essential role played by Mary and Joseph in the Incarnation of the Word who joined the Divine Nature with the human nature hypostatically—that is, in His single person. Mary belongs to this order, or this community if you will, because of her “fiat” (her “yes”) to be the Mother of the Word—offering her very flesh to the Second Person of the Trinity.
Joseph belongs to this order because of his “fiat” to be the spouse of Mary and the foster father of Jesus—becoming the roof of Jesus and Mary, and serving as the integral third member to the mystery of the Incarnation. An incarnation which was sustained and protected under the watchful care of Joseph who protected Jesus from Herod and untimely publicity, whilst providing for Him as a child. Through his chaste marriage with Mary Joseph also protected Mary’s dignity in the eyes of the world, and by extension concealed the mystery of the Incarnation until its time came to be revealed.
Joseph and the Incarnation
Concerning the Incarnation and the Holy Family, in connection with Joseph’s fatherhood, Pope Saint John Paul II writes:
Inserted directly in the mystery of the Incarnation, the Family of Nazareth has its own special mystery. And in this mystery, as in the Incarnation, one finds a true fatherhood… In this family, Joseph is the father: his fatherhood is not one that derives from begetting offspring; but neither is it an “apparent” or merely “substitute” fatherhood. Rather, it is one that fully shares in authentic human fatherhood and the mission of a father in the family. This is a consequence of the hypostatic union: humanity taken up into the unity of the Divine Person of the Word-Son, Jesus Christ. Together with human nature, all that is human, and especially the family – as the first dimension of man’s existence in the world – is also taken up in Christ. Within this context, Joseph’s human fatherhood was also “taken up” in the mystery of Christ’s Incarnation.
Joseph and His Marriage to Mary
In the same document, John Paul II goes on to unfold the importance of Joseph, his fatherhood, and his marriage with Mary:
As can be deduced from the gospel texts, Joseph’s marriage to Mary is the juridical basis of his fatherhood. It was to assure fatherly protection for Jesus that God chose Joseph to be Mary’s spouse… And while it is important for the Church to profess the virginal conception of Jesus, it is no less important to uphold Mary’s marriage to Joseph, because juridically Joseph’s fatherhood depends on it.
Marriages patterned on the union between Adam and Eve serve to make the two “one in flesh” (Gen 2:24); but the chaste bond of Joseph and Mary, brought about their oneness in spirit in a manner par excellence. “They were,” writes St. Ambrose in In Lucam, “one spirit”.
Devotion to Joseph as Inseparable from Marian and Christic Devotion
Our Lord states in the Gospels, “Therefore, what God has united together let not man separate” (Mk 10:9). In order for our life of devotion to heed this exhortation we must not divorce our Marian devotion with a devotion to Joseph; nor our devotion to Joseph from a devotion to Mary. For Mary and Joseph are one, and an authentic and complete devotion to both Mary and Joseph as a couple, and as individuals, depends on a mutual Marian and Josephine spirituality which is by its very nature as Christocentric as devotion can get. Since Mary and Joseph lead us to Jesus and do so in a way far better than we can manage on our own, since who is more expert in the ways of Jesus than his very own earthly parents?
Joseph not only leads us to Jesus, but more specifically, leads us to Jesus through Mary—and so our devotion to Joseph nourishes our Marian devotion. For just as “The Church’s devotion to the Blessed Virgin is intrinsic to Christian worship” (CCC 971) we might say devotion to Joseph is intrinsic to devotion to the Blessed Virgin Mary by the simple fact that the two have been made one. This is why after Mary, Joseph has been considered by numerous saints and theologians as the greatest saint, and in turn, after devotion to Mary (since devotion to Jesus occupies its own supreme category), devotion to Joseph has been held to occupy the highest place.
Along this vein Pope Leo XIII writes in Quamquam Pluries – his encyclical on devotion to St. Joseph:
In truth, the dignity of the Mother of God is so lofty that naught created can rank above it. But as Joseph has been united to the Blessed Virgin by the ties of marriage, it may not be doubted that he approached nearer than any to the eminent dignity by which the Mother of God surpasses so nobly all created natures.
The Three Hearts
Devotion to the Sacred Heart of Jesus and the Immaculate Heart of Mary—indicative of our Christic and Marian devotion itself—is at the heart of, and is the very heart of our Christian life of devotion. Yet we can hardly forget the Righteous, Chaste and Hidden Heart of Joseph which is one in an indissoluble union of grace with the superior Two Hearts of Jesus and Mary—which forms the habitation in which they abide. Together they are the Three Hearts, which are so close they look as though they were one, and indeed, whilst distinct, they are inseparably one in a union of the profoundest love.
Joseph, wise ruler of God’s earthly household,
Nearest of all men to the heart of Jesus…
Husband of Mary, loving and beloved…
Warming our hearts with love for God’s own Mother…
Saint of the dying, blest with Mary’s presence,
In death you rested in the arms of Jesus;
So at our ending [and now, on this day] Jesus, Mary, Joseph,
Come to assist us!
 Edward Healy Thompson, The Life and Glories of Saint Joseph (Charlotte, North Carolina: TAN Books, 2013), republished from the original published in 1888 by Burns & Oates, Limited, London, and M. H. Gill & Sons, Dublin, pp. 5-12.
 John Paul II, Redemptoris Custos: On the Person and Mission of Saint Joseph in the Life of Christ and the Church, Apostolic Exhortation, 1989, 21, available at http://w2.vatican.va/content/john-paul-ii/en/apost_exhortations/documents/hf_jp-ii_exh_15081989_redemptoris-custos.html
 John Paul II, Redemptoris Custos, 7.
 Leo XIII, Quamquam Pluries: On Devotion to St. Joseph, Encyclical, 1889, 3, available at http://w2.vatican.va/content/leo-xiii/en/encyclicals/documents/hf_l-xiii_enc_15081889_quamquam-pluries.html
 Solemnity of Saint Joseph, Husband of the Blessed Virgin Mary, Hymn for Morning Prayer, The Divine Office, for Australia, England, Wales, and Ireland, vol. II., 2006 ed., (HarperCollinsPublishers, 1974).