Throughout history people have tried to help us better appreciate this mystery. As he catechized the Irish people, St. Patrick showed them a three-leaf shamrock to illustrate that God is both one and three. But such a physical illustration makes it seem as though God can be divided into parts. Our faith, though, tells us that where one Person of the Trinity is all three are present. This is known as "circumincession."
Rublev's famous icon of the Trinity, based on Abraham's encounter with three angelic beings (Genesis 18: 1-15), is one of the most beautiful representations of the Trinity, but it can also be misleading as it depicts three individuals. Western art follows a similar path, showing the Trinity as Jesus with a cross, and the Father as an old, white-haired man, and the Holy Spirit as a dove.
Perhaps St. Ignatius Loyola is more helpful. He once had a vision of the Holy Trinity as three keys of an organ or a piano being played together and creating one perfect harmony.
We believe that God is one and three because Jesus said so. We see this especially in John's Gospel. Pope Francis said: "Jesus revealed this mystery to us. He spoke to us of God as the Father; he spoke to us of the Spirit; and he spoke to us of himself as the Son of God." We believe because Jesus promised to send "the Spirit of truth" who "will guide you to all truth" (John 16: 13). The Spirit continues to teach us through the Scriptures and the Church.
Pope Francis went on to speak of the practical implications of this great mystery. "Today's solemnity, while making us contemplate the amazing mystery from which we come and toward which we are going, renews for us the mission of living in communion with God and living in communion among ourselves on the model of the divine communion."
In other words, because our origin is from God who made us in the divine image and likeness, we're made by and for love--union with God and the communion of saints. We are not isolated individuals. No one sins alone, nor is anyone saved alone. From our ancestral parents to the present, what one person made in God's image does affects the whole. This is why we all inherit the sin of Adam and Eve.
Pope Francis went on to say: "The Trinity is the communion of Divine Persons who are one with the others, one for the others, one in the others: this communion is the life of God, the mystery of the love of the living God."
Again, since we are made in the image of God who is a Trinity of Love, we are called to live in communion with others. As Pope Francis put it: "We are called to live not as one without the others, above or against the others, but one with the others, for the others, and in the others" [emphasis in the original]. We know what it means to live with others and for others, but what can it mean to live "in the others?" One way of looking at this is through St. Paul's teaching on the Body of Christ. He writes: "God has so constructed the body ... so that there may be no division in the body, but that the parts may have the same concern for one another. If one part suffers, all the parts suffer with it; if one part is honored, all the parts share its joy" (1 Cor. 12: 24-26). This is the meaning of compassion. We live "in" others when we see things through their eyes and experience the pain and joy that they experience.
Pope Francis continues: "This means to accept and witness in harmony the beauty of the Gospel; experiencing love for one another and for all, sharing joy and suffering, learning to ask and grant forgiveness. In a word, we have been entrusted with the task of building church communities which increasingly become families, capable of reflecting the splendor of the Trinity and evangelizing not only with words but with the power of the love of God that lives within us" [emphasis in original].
This is the work of the Holy Spirit which theologians tell us is the love between the Father and the Son. St. Paul wrote that "the love of God has been poured out into our hearts through the Holy Spirit that has been given to us" (Rom. 5: 5).
Ultimately the mystery of the Most Holy Trinity is the mystery of love. God is, by nature, Love. Before creation God was a perfect communion of love, but it is the nature of love to share. God chose to share existence, life, and love with human beings. Though God was perfectly happy, God wanted, as it were, to have "playmates" (see Proverbs 8: 30-31). God wanted to share the delight of existence, life, and love with creatures made in the image and likeness of the Trinity. God created and "found delight in the human race" (Proverbs 8: 31).
All this raises several questions to use as we reflect on our day:
- How did I reflect the love of the Trinity today?
- How did I live with, for, and in others today?
- How did I give delight to God today?