For decades, god and religion have played no part in my life. I was baptised as a baby, but didn't make it as far as first communion. That may officially make me a Catholic in the broadest sense, but if it does, I'm one who's not so much "lapsed" as "stalled before I started".

Apart from morning assemblies and weekly hymn practices at primary school, followed by a couple of years of religious education classes at comprehensive (which I dropped as soon as exam options allowed), I have barely considered my immortal soul, much less the direction it may be heading when I die.

Over the years, when I bothered to think about it at all, I came to the conclusion that I prefer the scientific theory of life and the universe to the spiritual one. I'm most likely an atheist, but one leaning to the agnostic side of the spectrum. I know I'm a sceptic, in the true sense of the word. Or shallow. One of the two.

I was, however, inclined to agree when my wife, who's a pretty vehement atheist, said that she could cope with just about any life decision our children may make – apart from them wanting to join the military or the clergy. So what happened when our oldest daughter decided that, not only does she believe in God (capital G), but that she also wants to be baptised into the Catholic faith?

This shouldn't have been as big of a surprise as it was. About five years ago, work took me, my fellow-journalist wife and our then three-year-old child from eastern England to southwest France. We enrolled our little girl at a local Catholic school, selected purely on the recommendation of a colleague for the quality of its education. And frankly, the school had a place when we needed it. She has stayed at the same school, and we have had no cause for complaint. Quite the contrary. We have had every reason to thank our colleague for her on-the-money insight.

Being a Catholic school, an hour is set aside each week for catechism (aka "caté") lessons. Technically, our daughter should not have started going to caté as she's not (yet) Catholic, but we never thought to stop her and it's never been a problem.

A friend takes the class. She has often told us that our daughter is keen to learn and is visibly moved on high days and holidays, when the pupils are taken to church. But it's one thing taking caté in school. That's a bit like Catholic-centric RE (religion education for those who don't use that term). It's something quite different to want to go the whole hog and get baptised. And, it's apparently another thing again to knowingly want to be baptised.

At the risk of upsetting my parents, I have to say, I had no choice. I was baptised before I could have any opinion about it. Not that it matters. I was baptised. Other than talking about it here, it has had almost no impact on my life. End of story.

Our little girl, however, has made a life-defining decision by herself. I couldn't be more proud of her. But I cannot deny that what she said to my wife and I stopped us briefly in our slightly smug, religiously disinterested, bleeding-heart liberal tracks.

What courage had it taken for her to tell us what she wanted? It was clear that our brave, sweet daughter had thought about her faith long and hard.

Looking back, we realised we had regularly discussed our differing beliefs. Our daughter brought us Genesis. We gave her the Michael Bay-friendly Big Bang. She brought us the Nativity and peace and goodwill at Christmas. We gave her family, friends and good food. She brought us the crucifixion. We gave her the Easter Bunny. She brought us heaven, god and an afterlife. We gave her 21st-century life and a brief future as worm fodder.

After all that – and in spite of our gentle antipathy to god and creation – she still had the courage of her convictions to say to both of us, to our faces and again in front of the priest, that our world view isn't enough for her. She believes. She wants to be baptised and she wants to be Catholic.

For me, it means regular trips to the presbytery for extra "Catholic lessons". It means going to church for family mass on Sundays and not knowing when to sit or stand; and hoping that the priest doesn't come at me with the microphone when he delivers his Jerry Springer-style sermon (he probably won't).

It means a little extra effort on my part and no small amount of frustration for my wife, who tries – and often fails – to understand the attraction of all this. But it means everything to my daughter. She's taken a first step down a road that, ultimately, she'll have to travel on her own. I'll go with her as far as I can, but she knows, even now, that this is her journey. She's heading where I cannot follow.

I just hope that, the next time she faces a life-defining decision, she remembers this time when she told us she had faith in something we don't. And we believed in her.