Sermon on Trinity Sunday
By a Dominican Friar | 31 May 2023
“O the depth of the riches of the wisdom and of the knowledge of God!”
If we were to stop a passer-by in the street at random, and ask him what the purpose of human life is, what, I wonder, would he reply? Perhaps he would reply, especially if he is young, “the purpose of life is to have a good time.” Perhaps if he is older or less superficial, he might say that the purpose of life is to bring up one’s family well, or to make friends. If he is very idealistic, he might say it is to serve one’s fellow men. And if he has received an irreligious education, he might tell us that life has no purpose at all.
But all these answers would be either false or inadequate. As Christians, we are able to give the true answer to this question. The purpose of life is to enjoy and glorify the Trinity in Unity. That is why we were made: to know and love the one God in three Persons.
This has always been God’s plan for the human race, and so we can suppose that our first parents were aware of it, when they walked with God in the morning of creation. But the Fall of man placed a great obstacle in the way of realising this divine plan. Why was that? The Fall of man, among its other unfortunate effects, darkened the minds of men. As a result of this darkness, the human race came to lose its clear knowledge of the existence of one, only God. Men became incapable of making a clear distinction between the Creator and the spiritual beings whom we call angels, and they began to believe in the existence of many gods, and even to worship many gods. This is what we call paganism.
So, before man could be brought into a relationship with the three divine Persons, he had first to be healed of paganism. This is the reason why God called the Jews into covenant with Himself. God chose the Jews so that they would be the teachers of monotheism to the human race, that is, so that they would teach the rest of men that there is only one God. Through Moses, He gave the Jews a profession of faith, like our Credo but much simpler and shorter: “Hear, O Israel, the Lord our God, the Lord is one.” The Jews were not always good teachers, since like the rest of mankind they suffered from the effects of Adam’s fall. Sometimes they found their mission to be too heavy a burden; they longed to be like the other nations round about them, to cast off their monotheism and join in the rites of their neighbours. But God always brought them back, whether by glorious miracles, as when the prophet Elias routed the prophets of Baal on Mount Carmel, bringing down fire from heaven upon the sacrifice; or by stern punishments, as when the Jews were sent into exile in Babylon for 70 years; or again by the heroic example of warriors and martyrs, like Judas Maccabeus, or the unnamed mother and her seven sons who died rather than eat the food of pagans, contrary to the Law.
By the time of the incarnation, some two thousand years after the call of Abraham, God saw that the lesson had been sufficiently learned. The Jews were now fully convinced that there was only one God, the God of Israel. They had also been so spread about the world by the vicissitudes of history that they could teach this lesson to many gentiles. Mankind was now ready, therefore, to receive its next lesson. As St Paul says, “When the fullness of time was come, God sent his Son, made of a woman. What a wonderful new revelation, and what an honour for the Jewish people that they received it! The one God whom they already knew, eternal, immortal, all-powerful, and provident — He is not a solitary person, enclosed within Himself. He has a Son: and since a son must always possess the same nature as his father, this Son is Himself true God. With the one God, therefore, there is distinction: there is Fatherhood and Sonship, two co-eternal Persons.
Our Lord taught this lesson by His whole life. The Blessed Virgin understood it first: how could it be otherwise, since the Son of the Father is her Son also? But the apostles also came to understand it, no doubt at different speeds and with differing degrees of clarity. St Peter, above all, understood the lesson with the help of the Father’s inspiration, on the day when he says to Jesus, “Thou art the Christ, the Son of the living God.” But all those who conversed with Christ during His earthly life, or who heard Him preach, were able to learn the same lesson, if their hearts were right. He who has seen me, has seen the Father, He said to St Philip. And, by contrast, speaking of the rulers of the Jews, our Lord utters these sorrowful words: Now they have seen and have hated both me and my Father.
But before His earthly mission is complete, there is one more lesson to teach. Yes, there are two persons in God, but not only two. There is a third Person. Already in the Old Testament, the Jews had often heard about the Spirit of the Lord, who hovered over the waters at creation, or who came to the prophets to instruct them. But it belongs to the Son, from whom this Spirit proceeds, to teach the human race about Him clearly. Jesus does this above all at the Last Supper, when the apostles have made their first communion and their hearts are enkindled in a new way with charity. He tells them that this Holy Spirit of love is a third Person, co-equal with the Father and the Son. Just as the Father communicates the whole of His divine nature to the Son, in eternity, so also He grants to Him to be one principle with Himself of the spiration of the Holy Ghost. This is the glory which the Father gave to the Son before the world was made.
With this, God’s revelation of Himself to mankind is complete. Our Creator has revealed to us what we could never have known from creation: He, the one God, is a society of three divine Persons, a society of mutual love and knowledge. The Father knows and loves the Son and the Holy Spirit; the Son knows and loves the Holy Spirit and the Father; the Holy Spirit knows and loves the Father and the Son; each Person delights infinitely in the other Two, and each Person is the one God. This is the ultimate reality; it would be the same if no created thing had ever been made.
Did I say that the words of Jesus at the Last Supper completed God’s revelation of Himself? That is true, but there is one other thing to add. If He has revealed the Blessed Trinity to us, it is not only that we may admire it from afar, as we may admire reports about some city or land which we have never seen. We recite the words of the creed with a just pride, whether it be the apostles’ creed, or the creed of Nicaea which we say at Mass, or the magnificent Creed of St Athanasius, which sets forth the doctrine of the Trinity in the fullest and most perfect form. But these words are not enough to satisfy us. Who that loves another person could satisfy his love by reading a list of that person’s attributes, however correct that list may be? God wishes us to enter into His life: to know and love the Father; to know and love the Son; to know and love the Holy Ghost; to see Them, to hear Them and to be loved by Them. To enjoy and glorify the Trinity and Unity is the goal and purpose of our whole life.