May 30, 2010 is Trinity Sunday.  Also known as the Solemnity of the Most Holy Trinity, it falls on the Sunday after Pentecost.   

Catholics, Anglicans, Methodists, Lutherans and (many) Presbyterians celebrate this important feast day honouring the Triune God: Father, Son and Holy Spirit.  The celebrant wears white vestments.

Before Vatican II, the feast marked the end of a three-week period in the Catholic Church when weddings were forbidden.  This time period began on the fifth Sunday after Easter — Rogation Sunday — and ended on Trinity Sunday.

Traditionally, the congregation recited the Athanasian Creed on Trinity Sunday.  Now, this is done generally only by religious orders reciting the Divine Office and by orthodox Anglicans in accordance with the Book of Common Prayer.

Subsequent Sundays before Advent in the Church of England are numbered as being ‘after Trinity’.  This is according to the pre-Reformation Sarum Use.  Episcopalians number such Sundays as being ‘after Pentecost’.  Catholics now tend to use the term ‘Ordinary Time’, which begins the Monday after Pentecost.

Trinity Sunday has a special resonance in England, as Thomas Becket was consecrated Archbishop of Canterbury on this day.  It is a principal feast in the Church of England and the Episcopal Church.  St Thomas Becket’s first act as Archbishop in 1162 was to dedicate this day to the Holy Trinity.  The observance spread from England to the rest of Christendom.

Prior to that, the Church had no particular day devoted to the Holy Trinity.  The Office, which doctors of the Church instituted in response to the Arian heresy, was considered sufficient, as it was recited daily.  In fact, the ancient Micrologies record that this Sunday was designated a Dominica vacans (’empty Sunday’), with no special Office.  When petitioned to dedicate this Sunday to the Trinity, Pope Alexander II declared in the 11th century that the Creed and the Gloria Patri would suffice.  The petition arose because some bishops were already putting aside one Sunday a year to remember the Trinity.  Some used the Office which Stephen Bishop of Liege wrote in the 10th century.  Some places commemorated the Trinity the Sunday before Advent. In the 13th century, a Franciscan — John Peckham — later Archbishop of Canterbury, wrote a new Office for this feast.  Finally, a few decades afterward, Pope John XXII decreed that Trinity Sunday would be the Sunday after Pentecost, since it was on Pentecost that the doctrine of the Trinity became manifest to the world.

We cannot hope to ever understand the mystery of three Persons in one God.  It defies human comprehension, hence the reason why it is called a ‘mystery’.  The only ways we can try to comprehend it is through the seven gifts of the Holy Spirit as well as worship and prayer.  David Bennett, writing for, explains:

The Son is said to be eternally begotten of the Father, while the Holy Spirit is said to proceed from the Father through the Son. Each member of the Trinity interpenetrates one another, and each has distinct roles in creation and redemption, which is called the Divine economy. For instance, God the Father created the world through the Son and the Holy Spirit hovered over the waters at creation.

The Nicene definition of the Trinity developed over time, based on Scripture and Tradition. The Scriptures call the Father, the Son, and the Holy Spirit “God,” yet the three are also clearly distinct …

Ultimately, Trinitarianism posits a dynamic God, whose ultimate nature is beyond human conception, yet who voluntarily operates within the created world. Trinitarianism also shows a loving God that is willing to become as we are so that we may become like Him. The implications of believing in Arius’ God, a God unwilling to involve himself in our redemption, but who instead sent an angel of the highest order, did not escape the earliest Christians. As St. Athanasius was fond of saying “that which has not been assumed has not been redeemed,” meaning that unless God truly became completely human, we could not be fully redeemed, because only God Himself is capable of truly redeeming humanity; an angel does not have this ability. Thus, the Trinity is not about Greek philosophy or pointless metaphysical speculation, but about the heart of our salvation.

As with all great and wondrous divine mysteries, much more can be said.  I’ll pick up on this again next year.

(The icon pictured, by the way, is called The Holy Trinity.  St Andrei Rublev painted it — a rare Eastern Orthodox depiction of the Holy Trinity, using three angels to symbolise the Triune God.  St Andrei used ‘The Hospitality of Abraham’ as his theme.) 

For further reading:

Trinity Sunday – Wikipedia

All About Trinity Sunday

Trinity Sunday – Catholic Encyclopedia

Thomas Becket