On Trinity Sunday, we celebrate God as a Trinity of persons, Father, Son, and Holy Spirit. God the Father, out of love and from all eternity, begets the Son and gives to him all that he the Father possesses (see Jn 16:15). The Son returns the Father’s love and obeys the Father in all he asks (see Jn 17:10, 5:19). The perfect, self-giving love between the Father and the Son is itself the third person of the Trinity, the Holy Spirit. Our doctrine of the Trinity is vital for us as revealing the self-giving love that structures the universe. The truth of creation is not obvious, given the challenges of life. According to the Babylonian myth Enuma Elish, for example, humankind was created to serve the gods! (Tablet 6, v. 8). If God were motivated by human concerns, this myth would make sense, but Jesus reveals God as a loving communion of persons whose motive in creating is not to receive but to give (see Acts 20:35). God in fact gives human beings his very self, “The love of God has been poured out into our hearts through the Holy Spirit that has been given to us” (Rom 5:5). The Spirit dwelling in us reveals the depth of God’s love and empowers us to love him in return with a love that grows to become divine. As God’s love, so ours is a creative force offering life and healing to all to whom God sends us.