Some books make a lasting impression because they get you excited about something. They give you eyes to see the world anew. While reading, something slides into place, unlocking a universe of meaning.

The doctrine of the Trinity can be a source of deep embarrassment for people, and the notion that it’s something to be excited about – as opposed to sheepish – might be a bridge too far. Although the Church has insisted for generations that this dogma holds everything else together, there is no shortage of people who argue it is nonsensical, outdated, irrelevant, or unnecessary for the ordinary believer.

Somehow, generating excitement is exactly what Darrell W. Johnson accomplishes through his little book ‘Experiencing the Trinity: Living in the Relationship at the Centre of the Universe’ (2002). Against those who might construe the doctrine as the result of people living in an ‘ivory tower think-tank’, Johnson invites us to consider that the revelation of the Triune God is integral to the Good News Christians are called to proclaim.

It’s important to note the title: ‘Experiencing the Trinity.’ Not ‘understanding’ the Trinity or ‘grasping’ the Trinity or even ‘solving’ the Trinity: Johnson wants to get to the heart of the matter by asking whether this doctrine has any implications for the human experience.

Is it philosophical mumbo-jumbo? Is it an incoherent model dreamt up by people desperate to make their faith system work? Or is it a mystery that can be lived here and now? Is it a mystery that, like the sun, as C.S. Lewis said, helps us to see everything else?

For a short book (the Kindle edition registers 73 pages) it packs in a lot of excitement, which, again, is part of the point. Johnson wants us to fall in love with the Triune God. He wants us to recognise that the beating heart of creation is a love so intimate, so real, so life-giving, that we can’t help but fall in love with it. This love is inherently relational: Father, Son, Holy Spirit.

The excitement comes not just from this, but from the proposal that we are invited to step into that relationship; to share in the intimacy of the Triune God and become ‘co-lovers’, not just ‘believers’. We can live the Trinitarian mystery here and now.

This is something that affects even our experience of prayer, Johnson says. God is not merely someone we pray to. He is someone we pray in and through. As Catholics, we begin prayer with the sign of the Cross: in the name of the Father, and the Son, and the Holy Spirit. It’s important to reflect on what this signifies. Our prayer is spoken within the mystery of the Trinity, to the Father but through Christ and in the Holy Spirit. We have been given the extraordinary grace of living and praying within the communion of the Trinity, the royal court of divine love – not just approaching it from the outside.

If that’s not news to get excited about, what is?

Darrell W. Johnson is a Presbyterian minister, so the book lacks the rich sacramentality that soaks every fibre of Catholicism. The sacramental dimension of our life in the Trinity is no small loss, either: the sacraments God gave us are the very sources of grace by which we live the mystery and let it change us.

Even so, this book is an important one. It opens up the reality of the Trinity as an indispensable article of faith; as the doctrine that, once its light brightens the world, changes everything.

There is a tendency adrift in the modern era to seek ‘simply Jesus,’ without the baggage of doctrine or theology or anything like that. Johnson’s little book seeks to counteract this by suggesting that if we dispense with the Trinity, we have to dispense with Jesus also. There is no ‘simply Jesus’ without dogma. Dogma has been the slow and reflective process of coming to terms with who Jesus really is.

At the end of the day, dogma is not something abstract and distant from the lives of ordinary believers. It is an entry-point into understanding the mystery we get to live here and now. And it is an exciting mystery. The news that God is Trinity, that he is communion and fellowship and an eternal dance of love, is very, very good news. That we get to share in that communion is even better news. If you want to get a taste for that excitement, and pass it on to others, Johnson’s little book is dynamite.