Fr. Kyle Schnippel has an article up at Catholic Exchange on Understanding Celibacy Through the Theology of the Body

In the early parts of his papacy, Pope John Paul II delivered a series of Wednesday catechesis talks on spousal love. Built on his reflections of the first chapters of the Book of Genesis and refined during his trips as a young priest and bishop in Cracow, these talks have been coalesced into a systematic series of theology, collectively known as the Theology of the Body…In many ways, Pope John Paul II’s Theology of the Body gives the theological underpinnings for the teachings expressed in Pope Paul VI’s 1968 Encyclical Humanae Vitae.

However, because of the broad scope of these teachings, there is also an application to the Church’s understanding of the theology of the priesthood, and of one particular aspect of the priesthood in the Latin Rite: celibacy. In fact, John Paul spent an entire section of his Theology of the Body on celibacy, for he saw spousal love and priestly celibacy as complementary; which raises the question of how these two seeming opposites are related.

To answer this question, we have to turn back to Humanae Vitae. In this document on the regulation of birth in marriage, Paul VI has as his basis the recognition that every person is called to a life of fruitfulness, no matter his or her vocation. For married couples, this is naturally through the begetting of children. However, some couples are either incapable of childbearing or are beyond the normal age of childbearing; they are still called to a fruitfulness of life. This also applies to single men and women, as well as to those in a consecrated state of celibacy: men and women religious, priests and bishops. We are all called to give life. John Paul II’s reflections in the Theology of the Body help each one, according to his or her state of life, to recognize that unique way that God makes this invitation.

Read more and see these previous posts.