TRINITY SUNDAY

15th June 2025

Christian (Western Churches)

(Eastern Orthodox Christians celebrate All Saints at this time). 

Trinity Sunday, sometimes known as ‘The Solemnity of the Most Holy Trinity’, is celebrated in the West on the Sunday after Pentecost/Whitsunday, when Christians reflect on the mystery of God, who is seen as One but is understood in and through God the Father, God the Son and God the Holy Spirit. Orthodox Churches have no specific recognition of Trinity Sunday.

The Church has been celebrating the Trinity in its life and worship since its earliest days. Evidence of this can be seen in Trinitarian baptismal formulae. Many early liturgies and prayers refer to the persons of the Trinity, as well as collects, benedictions and doxologies that end with a Trinitarian statement: ‘The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all’. (2 Corinthians 13:14.)

The Trinity is one of the most fascinating – and controversial – of Christian teachings. It is described as a ‘mystery’. By mystery the Church does not mean a conundrum or a riddle, but rather that the Trinity is a reality above our human comprehension which we may begin to grasp, but ultimately must know through worship, symbol, and faith. It is ineffable as well as incomprehensible.

The Nicene definition of the Trinity developed over time, based on Scripture and Tradition. The New Testament calls the Father, the Son, and the Holy Spirit ‘God’, yet the three are also clearly distinct. The problem was that the Church had to reconcile the divinity of Jesus and of the Holy Spirit with Jewish monotheism. By the middle of the 2nd century the Church began using the word Trinity to describe this relationship between Father, Son, and Spirit.

Then in the 4th century a presbyter named Arius denied that the Father and Son were both true God and co-eternal, so that his bishop, Alexander of Alexandria, challenged and deposed him. Eventually the Arian controversy spread, and the emperor Constantine, newly fascinated with Christianity, convened a council of bishops in AD 325 in Nicaea to deal with Arianism. It was there that the Church drew up the beginnings of the current Nicene Creed, the bastion of Trinitarian belief.

Christianity adopted this complex view of the nature of God because it was the only way they could make sense of belief in the One God in the context of the events and teaching of the Bible. The idea of the Trinity does not supersede monotheism; it interprets it, in the light of a specific set of revelatory events: God the Father – revealed by the Old Testament to be Creator, Father and Judge; God the Son – who lived on earth amongst human beings; God the Holy Spirit – who filled the followers of Jesus with new life and power.

It is impossible to overemphasise the importance of this doctrine that God is one in three persons. This has correctly been called ‘the distinctive teaching of the Christian faith’, that which sets apart the approach of Christians to the ‘fearful mystery of the deity’ from all other approaches and beliefs. The creed, the fundamental statement of Christian belief, sets out the Trinitarian nature of God. Baptism is carried out ‘In the name of the Father, and of the Son, and of the Holy Spirit’. Eucharistic prayers are firmly Trinitarian in concept. The doxology is Trinitarian.

Relevant to the day are the natural symbols of the Trinity – the shamrock used by St. Patrick to explain the Trinity to the ancient Irish; the pansy – viola tricolour – called the ‘Trinity Flower’; a candle with three flames; the triangle; the trefoil; three interlocking circles; and so many others. They all seek to explain, though with only partial success, what is an inexplicable mystery.

Matthew 28:19; 2 Corinthians 13:14; John 1:18; 15:26.