Humanae Vitae is a prophetic document inasmuch as it touches on a critical point in which questions of sexuality, love, and life are intertwined. The heart of its message concerns the conditions under which a sexual act between spouses can truly be called an act of marital love. The encyclical argues that by deliberately rendering themselves sterile, the spouses change the nature of their sexual act, not only depriving it of its procreative, but also of its unitive meaning. The decades subsequent to the encyclical’s publication have demonstrated that sterilized sex indeed becomes trivialized sex. Once the dimension of potential common parenthood is excluded from its exercise, sexuality loses precisely the aspect that renders it so special. The essay highlights that Humanae Vitae’s teaching regards individual marriage acts in particular and not only married life in general. After presenting some pastoral considerations, it closes with the urgent reminder that questions regarding sexuality, marriage, and the family do not concern only some peripheral aspects of the cosmos of the faith but touch upon the core of Christian life and belief.