Trinity Sunday

Trinity Sunday is one of the few celebrations of the Christian Year which commemorates a reality and a belief instead of a specific person or event. On this feast day, we remember and honour God the Father, God the Son and God the Holy Spirit.

Christians believe that the Trinity is a mystery – a reality that is beyond human comprehension and that cannot be understood by reason alone. We believe that there is only one God but that God exists in three persons – the Father, the Son and the Holy Spirit. These three persons are not three Gods but one, yet they are distinct from one another. Each of the three persons of God - Father, Son and Holy Spirit – is equally God and the three cannot be divided.


This Trinity is revealed to us through the life and teachings of Jesus. He, the Son, speaks about his Father in heaven and He prays to him. He sends us the Holy Spirit, who is the love of the Father and the Son. We are clearly unable to deduce this reality by means of our human reason but must accept by faith God’s revelation in Jesus Christ. The Catechism of the Catholic Church gives a good explanation of the doctrine of the Trinity.


How did we come to have a special feast dedicated to the Trinity? In the fourth century, Arius, a Christian presbyter and priest in Alexandria, Egypt, professed his belief that Christ was a created being. By saying this, Arius denied the divinity of Christ and he also denied the Trinity. Athanasius, the chief opponent of Arius, upheld the doctrine of three persons in one God. This latter view was upheld by the Council of Nicaea.


To emphasize the doctrine of the Trinity, other Fathers of the Church composed prayers and hymns to be used in the Church’s liturgies and on Sundays as part of the Divine Office. Eventually, a special version of this office began to be celebrated on the Sunday after Pentecost. The Catholic Church in England, at the request of St. Thomas à Becket, was given permission to celebrate Trinity Sunday and the celebration of Trinity Sunday was made universal by Pope John XXII.


For many centuries, the Athanasian Creed, traditionally credited to Saint Athanasius, was recited at Mass on Trinity Sunday.