In the school chapel every morning, bored and tired, I’d rest my forehead on the back of the chair in front and try to doze. The chapel chairs were dignified and sturdy, each with its own wooden box for hymn books and a flat top, carved with the name of a generous old girl. As morning chapel progressed, that name would slowly etch itself into my forehead so that sometimes even at lunchtime I still had the name of a past and more perfect pupil stamped backwards above my eyebrows.

This is very much how I feel now about the Church of England. When you’re brought up in an institution, however soporific, it leaves its mark on you. I converted to Catholicism nearly two decades ago but I’m still imprinted with the C of E. I’m at home with flagstones and lady vicars and my mind is full of the strange images I formed as a child listening to the Book of Common Prayer. ‘I am not worthy so much as to gather up the crumbs under your table.’

Why does the Church of England so routinely make a person feel certifiable for trying to believe?

I don’t regret converting, but I find it sad that my English son, with Anglican grandparents, will never know Anglican things. So I sing him prayers from the hymn book at bedtime – ‘He Who Would Valiant Be’, ‘Dear Lord and Father of Mankind’ – and the other day when we were passing Westminster Abbey, I decided to visit.

There are few London sights as lovely as the west face of Westminster Abbey lit up by late afternoon sun, and as we approached the gate I felt a rush of patriotic pride: my boy would know his inheritance, I decided. We would kneel down here with Isaac Newton and Elizabeth I. It’s non-stop fun being my son.

A dour-looking man in uniform stood in the entrance by the abbey railings, but I walked up to him feeling confident. It’s £30 to get into the abbey for visitors (Blessed are the poor) but the rules allow for free private prayer. This was a chance to show my child that we are still, at heart, a Christian country. ‘We’re here to light a candle,’ I said to the dour man. ‘Can we come in?’ His face did not melt into a welcoming smile. I said, less confidently: ‘Private prayer is allowed, isn’t it?’

‘Your bag’s too big,’ he said. I took off my backpack and looked at it. Normal size. Just the same size as those carried by every one of the £30 tourists: water bottle, jumper, laptop, snack. ‘Is it a security thing?’ I asked. ‘Do you want to look inside?’

‘No. The bag is too big. You can’t come in.’

‘Well, can I leave it somewhere?’

‘No.’ The man looked at another near identical man standing opposite and some silent communication passed between them. He turned back: ‘There’s evensong at 5 p.m. every evening.’

‘But we’re just passing…’

In other circumstances I admire a man who can look down into the upturned, expectant face of a child and hold to the letter of the law. In this case, I felt pathetically heartbroken.

I know what the abbey’s communications team will say, that it costs £14 million a year to run and that visitors have been asked to cough up for centuries. The abbey is a ‘Royal Peculiar’, they’ll point out, under the authority of the King and more for ceremony than prayer. But this was once one of the most powerful churches in Catholic Christendom. Our history is here. Edward the Confessor, saint and king, is here. He’d enjoy a prayer before 5 p.m. Why does the Church of England so routinely make a person feel certifiable for trying to believe?

On the upside, as we turned away, I had a useful change of heart. Earlier this year there was outrage over plans to put on ‘silent discos’ in cathedrals across the country. A few have already taken place – hundreds of student types bobbing about in the aisles listening to tunes on headphones. The next great dance date is in Canterbury cathedral (not a Royal Peculiar) in February next year. I have in the past defended the idea of a silent disco, or at least thought: why not? The C of E’s ‘experience’ team are so touchingly excited by the thought of all those ‘young people’ in church. But it strikes me now that you can’t serve two masters. If you put the brand or the funding, the ‘experience’ or even the planet over the faith, you’re contributing to your own demise.

I went back to the abbey on Monday alone with a smaller bag this time and approached with less confidence, feeling very much as I do at the easyJet check-in desk. Will the bag fit in the overhead locker? Is it small enough for prayer? The doughy men were gone and a smart-looking lady was in their place. ‘Yes, you can pray for free, but you must stay on these wooden chairs by the entrance.’ I asked: ‘Isn’t there some sort of side chapel?’

The woman looked at me with sudden understanding. I was one of those prayer hustlers, trying to cop a look at Chaucer for free. Without saying a word, she ushered me briskly out into the cloister, where we walked the length of the nave outside. If she could have put a hostage hood over my head, I think she would have. We re-entered and made for a door by the south transept at breakneck speed, and then I was alone in St Faith’s chapel. I don’t quite have the words to describe it except to say that, although there wasn’t a tomb in sight, I’d happily have sat there all day. The abbey was once a monastery, I hadn’t known that, and this was once the monks’ vestry.

On my way out I kept my eye lowered in acknowledgement of my non-paying status. I did by chance catch sight of Thomas Hardy’s name on a plaque as I passed, though, which must have been worth at least 50p.