I hear the question and at once pull the blanket tighter around myself.

‘Mummy, who is the Holy Spirit?’

There’s nothing for a second. And then.

‘Ask daddy. Daddy will be able to explain it better than me.’

I lie still, hoping it will pass. But soon I’m being roughly shaken and I’m forced to sit up.

‘Daddy….daddy, who is the Holy Spirit?’

I’m rubbing my eyes, scratching my head and trying to stall for time. Usually I like a smoother passage into the day than this.

‘The Holy Spirit? Where did you hear about that buddy?’

The teacher told us in school. What does it mean daddy?’

I look pleadingly towards mummy but she’s facing the far wall with the blanket pulled to her ears. I’m sure I can see a small tremble in her shoulders which I think might be an attempt to smother laughter.

‘Well….uh…..the Holy Spirit…..it’s um….sort of a type of a spirit, I suppose.’

His little eyes are fixed on me. He’s not to be bought off by such a paltry answer. I delve deep into my memory, from a time almost four decades ago when this particular concept last troubled my thoughts. I’m not sure I understood it then, I’m sure I don’t now. His eyes haven’t moved. I try again.

‘Well, you see, some people believe different things about the origins of the world. Some people believe in a god, and some of those believe in a god which is divided into three. There is God the father, who you’ve been told about in school. Some people think he lives in heaven.’

‘God’s house in the sky near the sun daddy?’

‘Uh, yeah, I suppose so. And then there’s God the son, who some people believe is Jesus, who came down to earth.’

‘And has his birthday at Christmas?’

‘Well yes. Then the third part of God, some people believe, is the Holy Spirit.’

‘And what’s he like daddy?’

‘Hmmmm, well, it’s hard to be sure. Those who believe in the Holy Spirit think he’s like a presence, something which is everywhere and in everything we do.’

My son stares at me without comprehension. I’m beginning to regret starting this. I go on.

‘Sometimes the Holy Spirit has been depicted as a flame….or as a dove, which is a sort of bird.’

‘A bird which is on fire daddy?’

‘Yes, well, I think that’s just for illustrative purposes. I think the point is it’s supposed to be a feeling, rather than a thing. God’s presence on earth. When I was a kid we called it the Holy Ghost.’

‘He’s a ghost daddy? Like the ghosts in Muppet Christmas Carol?’

Again I look around for help, but none is coming. I’m well out of my comfort zone.

‘Well…not exactly like that. As I said, this is just what some people believe in. Other people have different ideas. The only truth is that nobody really knows.’

He stares at me hard for a second, almost as if he’s considering whether he should prolong my torture. Then….

‘Daddy, can I play on your phone?’

I quickly hand the mobile over, happy to be spared further interrogation. Soon he’s happily playing a game and humming along to a tune of his own making and I go downstairs to make breakfast. As I spread butter on toast I’m troubled by thoughts that I didn’t handle the encounter very well. That I made my son a lot more confused than he was before.

I know what my instinct wanted me to say. As a longtime and committed atheist I wanted to say that religion is a load of manmade superstitious nonsense and that the idea of the Holy Spirit is on the very far edge of the whacky scale. Leave no room for doubt.

But I didn’t do that. Partly because I don’t want to directly contradict something he has been told in the school classroom. While I’m far from convinced of the merit of introducing a five-year-old to an idea as woolly and opaque as the Holy Spirit, I’m more concerned about the disturb that might be caused by having him thinking his teacher and father are pulling in different directions.

But the bigger reason why I didn’t dismiss the Holy Spirit as obvious hoodoo is that, even though I’m his father, I’m not sure it’s my place to do so. He has the right, like every child, to make that decision himself.

While I’ve always been dubious about the wisdom of inculcating children in any narrow form of religion as an inalienable truth, it would surely be just as arrogant of me to simply expect him to share my humanist views.

Which is why I try to tell him everything, and about everything. And why, on occasions such as this morning, I get myself into a holy mess by bending over backwards to give all sides of the story and to be fair to everybody. Even when I believe the concept to be nonsense.

I’ve little doubt that my bumbling words this morning made no impression on his formative mind. But, as he gets older, more ideas will be introduced and more concepts will stick. His mind will learn how to reason, to make decisions based on evidence and to think critically. And he will learn about lots of religions, and science, literature and history.

And then at some point, when he’s ready, he will pick his own path. He may follow his father as an irreligionist. Or he may decide to follow a faith, after all there are certainly plenty to choose from. And that will be just fine.

Between then and now there will undoubtedly be many, many more questions. And more faltering, stuttering attempts at explanation. It’s all part of the journey of self discovery. For him and me.