The Most Holy Trinity | Fr Matthew Jarvis delights in the mystery of the Triune God who, as a beacon of Love, draws us ever further into glory.

‘Go, therefore, make disciples of all the nations; baptise them in the name of the Father and of the Son and of the Holy Spirit.’ Or more literally: ‘into the name of the Father and of the Son and of the Holy Spirit.’ That’s also what the original Creed says: ‘I believe into God the Father... and into the Son... and into the Holy Spirit.’ We are on a journey into God, a journey into the dynamic life of the Holy Trinity. It’s a journey into love.



‘I love you.’ Three of the simplest words in the world, but we use them to express an inexhaustible mystery in our human relationships.



‘God is love.’ Again, three simple words but they open up the infinite mystery of the Trinity.



‘The Lord is God indeed,’ we read in Moses today, ‘he and no other.’ Reason finds no problem in thinking of God as the Absolute, the One, but we need revelation to teach us about the Trinity: Father, Son and Holy Spirit. God is Three and God is One; both are true mysteries, and they are connected. To appreciate why we cannot fully comprehend the mystery of the Holy Trinity (God’s personal threeness), it helps to remember that we really cannot grasp the mystery of the Divine Simplicity (God’s substantial oneness) either.



The doctrine of divine simplicity states that God is not complex (made up of parts) in any way. Father, Son and Spirit are not parts of God, but One God. Easier said than understood! G. K. Chesterton recounts the story: ‘A lady I knew picked up a book of selections from St Thomas [Aquinas], with a commentary; and began hopefully to read a section with the innocent heading, The Simplicity of God. She then laid the book down with a sigh and said: “Well, if that’s His simplicity, I wonder what His complexity is like.”’



But God is not complex. The Platonists understood that simplicity is found at both the highest and lowest realities, both in the mere potentiality of ‘pure matter’ and in the luminous glory of the One. Is this what a modern American writer, variously cited as Ralph Waldo Emerson or Oliver Wendell Holmes Jr, is also saying? ‘I would not give a fig for the simplicity this side of complexity, but I would give my life for the simplicity on the other side of complexity.’



God’s simplicity is not like pure matter, because God is pure Actuality, white-hot Light, total and unconditional Love. This actuality envelops and drives everything, as its source and goal, the Alpha and Omega. I’m deliberately mixing philosophical language with Scriptural images, because both reason and revelation should guide us on our journey into the mystery of the Triune God.



Our journey into God’s simplicity will not take us back again to square one, empty-handed, but instead we will discover that a fullness has sent us out and a fullness will receive us home, transformed. There is a fullness in the simplicity that encloses complexity, like there is a fullness in the God whose eternity encloses time and is not enclosed by it. So, our journey into the Trinity is an attraction to the divine simplicity, not a stagnation in human simple-mindedness.



After all, there is a lovely simplicity in genius that differs from simple-mindedness. Often a beautiful object is found to have a simple rationale, despite its manifold appearance, whether it’s the mathematical iteration of the ‘Hofstadter butterfly’ or the musical unfurling of a Bach fugue.



We cannot draw the Trinity or compose its theme-tune, but there’s a decent medieval attempt in the simple yet profound pictogram called the Scutum Fidei (Shield of Faith) that summarises: the Father is God, the Son is God, the Spirit is God, yet the Father is not the Son and the Son is not the Spirit and the Spirit is not the Father.



The Trinity does not undermine the simplicity of God, because there’s nothing simpler nor stronger than persons united in love. The unity of God is a perfect communion of persons. And then St Paul pronounces God’s extraordinary invitation to us: receive the Spirit of God, let God dwell within you and make you his child, his heir, and take you into his glory.



The Light is too bright for our eyes right now; it’s too pure and simple, but it beckons us, a beacon of Love, drawing us ever further into glory – into the Father, and into the Son, and into the Holy Spirit.

Deut 4:32-34, 39-40 | Rom 8:14-17 | Matt 28:16-20

Photograph by Fr Lawrence Lew OP of the 'scutum Fidei' depicted in a window in the church of St Denis in Hanover, MA.