With one exception all the Church’s festivals are concerned with God’s activity in human affairs in general and in the lives of individual people in particular. Obvious examples are Christmas, Easter, Ascension Day and Pentecost; and the various days in honour of Our Lady and the Apostles and Martyrs and all the other heroic witnesses to God and his truth.

This one exception is today, Trinity Sunday, which is concerned not with what God has done and is still doing in the world, but with his Being. It is a joyful celebration of God for his own sake – because of who and what he is in himself.  And it calls forth from us the adoring recognition of his perfection – loving him because he is truly lovable, praising him because he is worthy of all praise, and honouring him because honour is his rightful due.

Such is our response to the revelation of his Being, of Three Persons and One God, of one eternal Trinity in one undivided Unity. That truth has been made known to us through the life and teaching of Jesus Christ who himself summarised it before his Ascension when he commissioned his Apostles “…to make disciples of all nations, baptizing them in the name” (not names) “of the Father and of the Son and of the Holy Spirit…” (NRSV, Matthew 28:19).

We can trace the steps by which Our Lord’s teaching culminated in that sublime statement of fact; and we can see how the Early Christians confirmed it for themselves in their own experience as they were conscious of the Father and the Son and the Holy Spirit at work in their own personal lives.

Later the doctrine of the Trinity was elaborated by the Early Church in the Nicene and Athanasian Creeds, not in order explain it but rather to rule out erroneous explanations and to safeguard the truth of the facts, revealed by Our Lord and enshrined in the Scriptures, from being undermined by human speculation.

It is noteworthy that the great Christian writers of the Early Church, the Church Fathers, deplored the necessity, in defence of true religion, to formulate technical theological definitions of the Being of God, which they did not believe to be a proper subject for human analysis and definition. For them, it has been well said, “…the ground they trod was holy ground, the mysteries they handled, things of awe”. (1)

One such was St Hilary of Poitiers in the fourth century who combined a powerful intellect with a profound reverence. In his Treatise On the Trinity he wrote, “Faithful souls would be contented with the word of God, which bids us ‘Go teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost’. But alas! we are driven by the faults of our heretical opponents to…scale heights inaccessible, to speak out what is unspeakable, to presume where we ought not. And whereas it is by faith alone that we should worship the Father, and reverence the Son, and be filled with the Spirit, we are now obliged to strain our weak human language in the utterance of things beyond its scope…”. (2)(our emphasis)

So wrote St Hilary, and his words are as true now as then. Human beings cannot comprehend the incomprehensible. Only God can understand himself.

Our true response to the doctrine of the Trinity is faith, not just an intellectual assent to the Gospel teaching, but a trustful commitment of one’s whole self to God as he has revealed himself to us; and the supreme expression of faith is worship and adoration.

So the Athanasian Creed itself begins, “And the Catholick Faith is this: That we worship one God in Trinity, and Trinity in Unity…”. (3) And that is echoed in the Nicene Creed in which we declare our belief "…in the Holy Spirit...who with the Father and the Son is worshipped and glorified..." (4)(our emphasis)

And there are two other facts revealed to us about God in Holy Scripture which give to our worship, first its moral character, and secondly its spiritual vitality.

The one concerns his absolute perfection: “…God is light and in him there is no darkness at all” (NRSV, 1 John 1:5). The other points to the doctrine of the Trinity without which it would have no real meaning. That second fact is, not that God is loving though that is true, but that “God is love…” (NRSV, 1 John 4:16, our emphasis), that he is in himself absolute, infinite and eternal Love.

But love necessarily means the love of one person for another and therefore eternal love is the love of a plurality of Eternal Persons within the Being of God – that mutual love which is for ever given and received within the Trinity and which overflowed into the Creation of the Universe, and the redemption of the world, and the sanctification of believers by the Three Persons in One God.

So Trinity Sunday is not what at first sight it might seem to be. It is not the commemoration of an abstruse, metaphysical concept. Rather, it is a day of joy in God himself as he is in all his eternal love and goodness: the God in whom “…we live and move and have our being…” (NRSV, Acts 17:28, our emphasis): the God who has revealed himself to us as he is, so that we in turn may respond by loving him and obeying his will, and, in so doing share in his Being and his life both here and hereafter (see 2 Peter 1:4).

References

1. Illingworth, J.R. (1898) Divine immanence, London: Macmillan and Co Limited.

2. Hilary of Poitiers (4th century) On the Trinity, cited in Illingworth, J.R. (1898) Divine immanence, London: Macmillan and Co Limited.

3. Book of Common Prayer (1662) Athanasian Creed. Available from: http://www.churchofengland.org/prayer-worship/worship/book-of-common-prayer/the-creed-of-s-athanasius.aspx (Accessed 05 June 2014)(Internet).

4. © The Archbishops' Council of the Church of England (2000) Common Worship Creeds and authorized affirmations of faith. Available from: http://www.churchofengland.org/prayer-worship/worship/texts/newpatterns/contents/sectione.aspx (Accessed 09 June 2014) (Internet).