Today we celebrate the mystery of the Holy Trinity.  It is a mystery that is part of our Catholic DNA, but we seldom reflect on it.  When we make the sign of the Cross, we say: “In the name of the Father, and of the Son, and of the Holy Spirit.”  We baptise people: “In the name of the Father, and of the Son, and of the Holy Spirit.” When the priest dismisses us at the end of the Mass, he blesses us: “In the name of the Father, and of the Son, and of the Holy Spirit.” 

We believe and celebrate often that God is one and God is three even though it is a mystery that we cannot explain.  We believe it because this is what Jesus has revealed to us.   For the Jews at Jesus’ time (and for many still today) this is heresy; in the Hebrew Scriptures God is revealed as One. For the gentiles at that time (and still for many following different religions today) it was a stumbling block; they believed that there were many gods, not just One.

For the first three hundred years after Jesus’ resurrection the Church struggled to find a way to talk about this mystery.  There were those who affirmed that God is one and the Father, Son, and Holy Spirit were just three different ways of looking at the one God who creates, redeems and sanctifies us.  The names represented three faces, but they did not indicate three distinct “realities”.  There were others who said that since Jesus said he was God, then there must be at least two Gods, perhaps having a relationship with one another but not forming a unity.  After many disputes, excommunications, and schisms the Church Fathers resorted to Greek philosophy and defined in 381 that God is one in “substance” but also three distinct “persons”.  And since 381 this is the way that Catholics still talk about God being one and three at the same time.  It is not an explanation, but it is a way to being true to what has been revealed by Jesus without resorting to claiming one God who has three appearances or to three Gods.

I often wondered why God chose to reveal this truth about God-self when God certainly must have known that we would never be able to understand this truth in this life.  The only explanation that made sense to me was that God loves us and God wants us to know the truth about who God is and about how God’s life is lived.  I grew up with four older sisters and I could never understand how they could spend so much time talking with their boyfriends when they came courting.  I was happy when the boyfriend gave me and my sister money to go off to the movies so that he could be alone with my sister.  But I was surprised they didn’t run out of things to talk about.  As I grew older I discovered that when I really loved someone I wanted them to know me as I really am, and that took time.  There were times when my self-disclosure must have confused the other pserons.  But I wanted them to know the truth about me.  That is why I think that God’s self-disclosure, even if it confuses us, is a sign of how much God loves us.

Since we are made in the image of God there are two things about this mystery that we must keep in mind.  We are made to be One and we are made to be more than One.  We are made to be in a close relationship with others.  We are not meant to be “loners”  -- “an island”.  God made us in a way so that we need others.  But, in imitation of God, we are meant to be One with these others by getting to know and love them.  Jesus prayed for his disciples: “that they may be one, as we are one – you in me and I in you.”  And the commandment He gave us was: love one another. It is in this way that we become fully human and share in the divinity of God: by loving others to the point that we become one with the other.  This can sound like a remote ideal, yet this is the way God made us.  We will not be completely happy until we love the other so much that we become one with him or her.  It is indeed a great mystery.