When Fathers’ Day began to be celebrated, it was more or less taken for granted that a child knew who was his or her father. That is not always the case now and, as we celebrate Fathers’ Day this year, it might be good to look again at what the absence of fathers in their lives does to children. In marriage, a man and a woman are not interchangeable. Both are needed for the unity “in one flesh” that is distinctive about marital love and both are necessary to conceive and raise a child. Opening oneself to the opposite sex is a step toward opening oneself to others, to our neighbors and even to the Other who is God. Those who would downplay or even deny sexual difference belong to the group that Pope Francis calls “uniformists.” Everyone has to be the same, or at least we have to pretend we are. In Scripture, the original communion of life between man and woman, founded on a reciprocal and personal relationship, is eroded by sin. Woman goes from being a companion to man, gifted with equal dignity, to being often pictured as his subordinate. Polygamy and divorce were introduced, and families become clans. The prophets, however, often recalled the original truth of marriage, in which the wife and husband are true partners, each contributing differently to a new family, cooperators with God in creating new life and expressing new love. Jesus taught clearly “what was from the beginning.” (Mt 19: 3-6). For this reason, St. John Paul II called marriage “the oldest sacrament.” But Jesus also, in opening up the life of virginity as a sign of the transcendent Kingdom of God, made marriage a choice and not a duty. Already in the second century, Christian marriage was recognized as something more than what pagan society knew. The Letter to Diognetus relates that “Christians marry as everyone else does and have children, but they do not abandon the newborns; they share their food but not their wives.” Intact families that recognize the central importance of expressing love as a gift of self, that respect the dignity of women in marriage and understand that the human couple in marriage is an image of God’s unity in diversity of persons are the answer to many of the personal and social sins that beset us today. When I was a seminarian, I read one of Fulton Sheen’s books, “Three to Get Married.” The archbishop was writing of husband, wife and God, each of them indispensable in creating the loving and fruitful union that is true marriage, each of them playing a distinctive role. Now, God is often removed from marital reality, followed by husband and father. The results are in the headlines of the daily newspapers and in the social statistics on the fraying safety net for children and the prevalence of violence. To discover who they are, children need a father and a mother, and they have to know who they are. Fathers’ Day starts with thanking fathers, but it can also be an occasion to strengthen families, rightly called the “domestic church,” as well as our spiritual homes, the parishes and other ministries directed by the ordained priests we call “Father.” On the Feast of the Most Sacred Heart of Jesus, June 27, the entire church has been asked to pray for the sanctification of priests. The Gospel is proclaimed with joy when our relationships are in order — to God and to one another in the communities God has given us. May this Fathers’ Day be filled with the joy and peace that accompany our life together in Christ’s family.