Understanding Sex Through the Mystery of the Trinity One of my friends has been trying to explain the Theology of the Body to one of his friends, and asked for a good way to explain what Catholics mean when we say that sex should be "unitive and procreative." What we mean is that: Unitive : Sex should draw the husband and wife together into a more perfect union with each other; that through it, "the two become one flesh" ( Genesis 2:24 ), in a way fully knowable only to God. Procreative : Sex should call forth new life, or at least be open to it. Authentic love isn't jealous, it's creative. To understand sex, I think you need to understand the Trinity. In the Trinity, God the Father loves God the Son, the Son is Beloved, and the manifestation of that Love is the Holy Spirit. Fr. Barron does a good job explaining that here . It's precisely because of that Love that God made the Universe and everything and everyone in it. So the Trin