I'm sorry to say that several of the worst homilies I’ve ever heard were given on this Feast-day.  They were all variations on a theme: faced with the insurmountable mystery of the Holy Trinity that this Feast celebrates, the preacher admits defeat and proceeds to torture the ears of his congregation with some nonsense about last week’s fishing trip.  I do understand this impulse: the Trinity is hard and it takes real effort to think about it and talk about it well.  But no effort could possibly be better spent.  It’s true that the Holy Trinity is a great mystery.  The greatest mystery in fact.  It’s the mystery of the nature of God.  The most sublime possible reality.  And yet, we are not helpless in the face of it.  There are things we can know about the Trinity, things which can truly affect and enrich our lives, which is why the Church places this Feast so prominently before us each year.  Because of what a sacred mystery is.  It’s not the kind of mystery you watch on CSI: where there’s something you don’t know (like who did it); then you find clues, apply some brilliant deduction, and then you know it: who done it.  Now in a literary mystery like this, there is a process of discovery, which is why it’s fun to watch.  And a religious mystery is a process of discovery too; but any Mystery of our Faith, especially this one, is different because it’s an endless process of discovery. You never get to the end of the episode. It won’t be tied up neatly at noon when we get to the end of this episode of Church.  It’s not that kind of mystery.  It’s not that we can’t know anything about God: it’s not that we can never know anything.  It’s that, we can never know everything about him.  No matter how much we discover, there is always more: an infinite depth of meaning to be plumbed.  The Holy Trinity is the highest mystery that there is, and thus the most inexhaustible. It provides the most unending and fulfilling process of discovery we could possibly have.  

The Church places this Feast-day at the end of the Easter Cycle, because it’s a “so-what?” Feast.  A Feast that summarizes everything that’s gone before, all the way back to December and the start of Advent, through Christmas, Epiphany, the Presentation of the Lord, Lent, Holy Thursday, Good Friday, Easter, the Ascension, and Pentecost.  All these mysteries have told us so much about God.  Today we pull it all together.  After all this, after these months of remembrance and ritual and mystery, what do we know about God now?  We’ve now the sovereign activity of God the Father; we’ve now seen the teaching and the life and death of Jesus Christ his Son; we’ve now seen the sending of their Spirit to animate the Church which remains here on earth: we’ve seen that God is three: he is a Trinity.  We have seen each person, Father, Son, and Holy Spirit as clearly unique: the Father is not the Son, is not the Holy Spirit.  They’re not just different ways that God speaks to us.  They are three persons.  And yet, they are so intimately close, that they can’t be distinguished like you and I can be.  They’re not just members of the same species.  The Church has never permitted us to speak of three gods.  But one.  An eternally dynamic movement of perfect Love.  God is Love.  And these relationships within the Trinity are perfect Love.  This is our radical Christian notion: God is love, even within himself.  God is relationship, even within himself.  And that relationship is so perfect and so complete, that they are as one. They are one.  

This is so critically important because we are made in the image and likeness of God.  We’re told this again and again in so many ways.  We are made in the image and likeness of God.  This doesn’t mean that God is 5’10” and nearsighted.  God is, by nature, relationship.  We are made in his image and likeness.  That means that we are made for relationship too.  That’s why this mystery matters for our life so much: God is Trinity and we are made in his image and likeness.  This means that we discover who we truly are in our relationships.  We can never be fulfilled looking out for #1.  We will never be happy as long as we’re obsessed with maximizing our own comfort and pleasure and prestige.  If man lives life as an island, he will be miserable and profoundly alone.  We are made for and fulfilled by relationship.  We are most like God when we give ourselves totally away in love: when we empty ourselves completely for others.  We are made to be like God: to discover who we are through the richness of our relationships of love.  God gives us the help we need to overcome our selfishness and live this way, through grace: through the Sacraments, especially the Most Holy Eucharist, God pours his life into our hearts: he gives us a taste of this eternal relationship of Love which is the life of the Blessed Trinity.  A life, please God, that we will share in fully one day, in the eternally unfolding mystery of Heaven.  Glory be to the Father, and to the Son, and to the Holy Spirit, as it was in the beginning, is now and ever shall be, world without end.  Amen.