This Sunday we celebrate the Trinity, the most obscure but also most glorious mystery of our faith.
Historically, this feast has two origins. First, it is the Octave of Pentecost. In the early middle ages, there grew a practice of recelebrating a feast one week afterwards, and every day in between. Divine Mercy Sunday is the Octave of Easter: it is like the whole week repeats the glory of Easter, and the liturgy even says that “today” is Easter throughout. One day cannot contain its glories. Christmas, too, has an octave. Pentecost was the third to get an octave – and after that, they started giving octaves to all sorts of lesser feasts.
Now, Easter season is the octave of octaves. Pentecost, the Sunday after seven weeks of seven, is the final day of this super-octave. It seems to be in for this reason that they dropped the Pentecost octave in the reform of the liturgy after Vatican II – we should think of Pentecost as part of Easter, not a separate season. But we retain Trinity Sunday as kind of a reduplication of Pentecost – that is, as a celebration that Jesus the Son of God, the victor of Easter, and the Holy Spirit, whom he pours into our hearts, are truly God from God, light from light, true God from true God.
There was also an independent tradition that at some places had a Trinity Sunday as the final Sunday before Advent, as the culminating feast of the Church year. The readings at the end of the year point to the end of time, and the readings of Advent to the second coming of Christ. Thus a feast was added to ponder the final mystery, the mystery in which all things culminate, the life of God.
And in fact, before Vatican II the liturgy for the feast focused less on the mystery of the Trinity than on the mystery of God. The first reading (they didn’t used to have an Old Testament reading) was from Romans: “O the depth of the riches both of the wisdom and knowledge of God! How unsearchable are His judgments, and His ways past finding out! For who has known the mind of the Lord, or who became His counselor?”
The Gospel had the Baptismal formula from the Great Commission, but juxtaposed with Romans and the other prayers of the day, the point seemed only to be that we are baptized into the mystery of God. That is part of what Trinity Sunday does: it just leads us to think about God. It is the feast of God – and the feast of the mysteriousness, the unthinkability of God.
Preachers are sometimes scared of Trinity Sunday. But we should dwell on that: that we cannot understand God is precisely the point.
And yet the readings of the reformed liturgy do lead us into a meditation on the three persons. The first reading, from Wisdom, talks about the wisdom, the Logos, who was in the beginning with God, through whom all things were made (as John says in his prologue). Although the tradition would probably focus on the Son, you can think of it speaking of the Spirit, too: “When the Lord established the heavens I was there, when he marked out the vault over the face of the deep,” etc.
We ponder, at the end of this Easter season, the true identity of the Son and the Spirit. True God, in the beginning with God.
The first reading from the New Testament, from Romans, is more specific.
“We have peace with God through our Lord Jesus Christ, through whom we have gained access.” The whole point of the original controversies about the Trinity, in the fourth century, was that Jesus can only give us access to God because he is God – and man. A bridge must reach to both sides: if he is less than God, he cannot connect us to God. But he is that great, that awesome – and our redemption is that great.
So too the Spirit: “the love of God has been poured into our hearts through the Holy Spirit that has been given to us.” Not something less than God, but God himself, as love. How great is our dignity!
And this is our hope even in “afflictions”: through the trials of life, we are in union with God himself, nothing less.
Most specific of all, of course, are the words of Jesus, from the prayer at the Last Supper in John’s Gospel. The Spirit “will take from what is mine and declare it to you,” and “everything that the Father has is mine.” Jesus can lead us to the Father because he is true God, nothing less. The Holy Spirit, poured into our hearts, unites us to Jesus because he is true God, nothing less.
How great is the mystery of God! And how great is our Redemption! Glory to the Father, and to the Son, and to the Holy Spirit!
How would your day be different if you really believed that God himself was at work in your heart?