The Feast of the Most Holy Trinity was celebrated this year on May 26. It is closely related to the Feast of Pentecost which was celebrated the previous Sunday because it is through the continuing work of the Holy Spirit that our belief about this great mystery of the inner life of the Godhead has been sustained and clarified.
One of the great functions, so to speak, of the times of the Old Covenant was to build a People of God who were firmly and irrevocably committed to the belief that there is only One God, the God who had revealed himself to them starting with Abraham. It was not easy, and the many woes of the Old Testament times illustrate the tendency of the descendents of Abraham to become part of the pagan cultures surrounding them with their gods for this and for that. It seems to me that the great story of the Maccabees is that they were finally willing to suffer and die for their belief in the One God.
Now the stage was set for the One God to reveal the inner life of the Godhead, that in the One God there are three Divine Persons named Father, Son, and Holy Spirit. The revelation was gradual. With the benefit of hindsight, we can see an allusion to the Holy Trinity in the visit of God to Abraham who “lifted up his eyes and looked, and behold, three men stood in front of him” (Gn 18:2). At the beginning of the public ministry of Jesus, he is baptized by John. As soon as Jesus came up from the water “the heavens were opened and he saw the Spirit of God descending like a dove, and alighting on him; and lo, a voice from heaven, saying, ‘This is my believed Son, with whom I am well pleased” (Mt 3:16-17). In the Transfiguration, the voice from the cloud repeats this message and adds “Listen to him” (Mt 17:5). The gospel of Matthew concludes with the Great Commission that includes the clearest statement of Trinitarian life of the One Godhead. “Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit…” (Mt 28:19).
These revelations did not answer all the future specific questions that would arise, for example, about the relationship of Jesus and the Triune God. Jesus had taught us the Sacred Reality, but he knew full well that questions would arise. What should we believe about the nature of Jesus himself? Some would affirm that he is true God and true man, but others would deny it. How can we know for certain what is true?
It is highly significant that the Gospel reading for Trinity Sunday comes from the Last Supper words of Jesus. “I have much more to tell you, but you cannot bear it now. But when he comes, the Spirit of truth, he will guide you to all truth” (Jn 16:12-13).
The bottom line is this. We can know with the certainty of faith that what the Church teaches about God is true because we believe that Jesus keeps his Last Supper promises. And as to why we should believe Jesus, his words are confirmed by his resurrection from the dead. As St. Paul wrote, “If Christ has not been raised, then our preaching is in vain and your faith is in vain” 1 Cor 15:14.
Thanks be to God for the life and teaching, the passion and death, and the resurrection of the Lord Jesus. Glory be to the Father and to the Son and to the Holy Spirit as it was in the beginning, is now and will be forever. Amen.