The title of St. Joseph, Most Chaste, is the last of the titles from the Litany included in the St. Joseph Chapel. Pope Francis talks about this virtue and title of St. Joseph in his Apostolic Letter Patris Corde. In the letter, Pope Francis states:
“That title is not simply a sign of affection, but the summation of an attitude that is the opposite of possessiveness. Chastity is freedom from possessiveness in every sphere of one’s life. Only when love is chaste, is it truly love. A possessive love ultimately becomes dangerous: it imprisons, constricts and makes for misery. God himself loved humanity with a chaste love; he left us free even to go astray and set ourselves against him. The logic of love is always the logic of freedom, and Joseph knew how to love with extraordinary freedom. He never made himself the center of things. He did not think of himself but focused instead on the lives of Mary and Jesus” (PC 7).
Chastity means being able to love others without the desire to possess them or use them. It means loving without fearing that I might not get what I need or want from the other person. It means loving with “extraordinary freedom.” That’s what chastity is ultimately about: freedom. The Catechism says that Jesus is “the model for all chastity” (CCC 2348). Jesus’ entire life is our model of loving others without condition or possession. The Cross is the perfect image of chaste love, love freely given for without the expectation of anything in return.
This promise of love free from possessiveness is compelling because it is the kind of love we were created by and created for. Pope Francis teaches, “God himself loved humanity with a chaste love.” This reflects the teaching in the Catechism that “God is love and in himself he lives a mystery of personal loving communion. Creating the human race in his own image. …God inscribed in the humanity of man and woman the vocation, and thus the capacity and responsibility, of love and communion” (CCC 2331). The deepest desire of our hearts is to experience love that does not desire to possess or use and to love others unconditionally in return.
From: https://wherepeteris.com/joseph-the-most-chaste/
This insight into the title Most Chaste helps also to make sense of the vow of chastity that the Sisters of St. Joseph made. Having St. Joseph as an example and guardian of chastity would help them to live this out. Being open to love others without the desire to possess or use them frees the sister to be able to listen to and better help the “dear neighbor” in whom they see the image of Jesus. Chaste love helps one to live in community as it is focused on the other and not on self.