This Sunday we observe the feast of the Trinity, the only major Christian festival that features a doctrine of our faith rather than an event in its sacred history. It has been a feast day in the Western Church since the ninth century and it celebrates the central mystery of our faith because the doctrine of the Trinity alone informs us who God is. To quote one source: “It is the mystery of God in himself.” And where does the unfolding of this mystery begin? Like the entire sweep of the biblical account of our salvation history it begins in Genesis when God says: “Let us make humankind in our image, according to our likeness… .” In other words, in the beginning there was a pluralism of God…God the Father, God the Son, and God the Holy Spirit. And it is a truth of our faith, along with the reality of how our Trinitarian God has revealed himself to us, that we acknowledge today through our liturgy of Trinity Sunday. God, our Triune God, has revealed himself through the historical facts recorded in scripture of the Incarnation of the Son at Christmas and the coming of the Holy Spirit at Pentecost. It is the revelation of these events, these truths, these realities, the deepest mystery of our faith, that we celebrate on Trinity Sunday.

But have you every wondered why we celebrate Trinity Sunday when we do…immediately following Pentecost? For these past six months, beginning in December with Advent and concluding in May with Pentecost, we have witnessed and been part of the events of Christ’s life; for example, his birth, baptism, temptation, calling his disciples, ministry and miracles, healings, betrayal, trial, crucifixion, resurrection, appearances, ascension. We have also experienced the coming of the Holy Spirit at Pentecost and the bestowing of spiritual power and the gifts of the Spirit. And now we have entered the Season of Pentecost, in a real sense our season. With Pentecost the Mystical Body of Christ, the Church was birthed, and with it our call for spiritual growth and action. It is no accident that the liturgical color for the Season of Pentecost is green, the color of growth. In addition, the scriptures chosen for the Liturgy of the Word this Trinity Sunday includes two instances that emphasize mission and growth through change. The first is from Isaiah (6:8): “Then I heard the voice of the Lord saying, ‘Whom shall I send, and who will go for us?’ And I said, ‘Here am I; send me!’” The second is from the Gospel according to St. John (3:6-7): “What is born of the flesh is flesh, and what is born of the Spirit is spirit…You must be born from above.” Therefore, in his dialogue with Nicodemus, Christ is essentially saying that to be a disciple of his you must be born again. With the coming of Pentecost and the Holy Spirit we are now equipped, empowered, and “called” through our rebirth, born from above, to bear fruit in building up the Mystical Body of Christ, the Church.
Why is this important and meaningful? It is a peculiarly curious paradox that while we, as Christians, acknowledge that much of what we believe to be mystery and we take on faith, our Trinitarian God nevertheless reveals a lot about himself…or should it be themselves. He/They have revealed a huge amount about themselves through scripture and the incarnate son, Jesus Christ (John 14:9): “Whoever has seen me has seen the Father.” We know he/they created us in their image and likeness. We know they have bestowed upon us the power of their Spirit. We know that we share in their plan for our redemption and salvation. We know that they prepare a place for us in their heavenly kingdom and that we will share in their heavenly banquet. We know that they want us to be one as they are one. So as we “ponder the impenetrable” this Trinity Sunday through our liturgy keep in mind how much has been revealed and why it has been revealed…because they love us.