Five-minute memoir: Jenn Ashworth recalls the day of her full-immersion baptism

My mum, in consultation with our bishop, decided to postpone my baptism until after I got home from Brownie camp. Mormons like to baptise their children as soon as possible after their eighth birthday, which is when they start to become accountable for all their wrongdoings. I'm a mid-August baby and my baptismal certificate is dated 9 September, 1990. I remember mum telling her friends (I wonder why she was asked?) that the postponement was to do with her wanting to make sure that the excitement about Brownie camp was "out of my system" before the baptism.

There might have been more to it, though. There was a lot of sewing going on, I remember. A bear's paw patchwork quilt for taking with me to camp, the first time I'd slept away from home, and a white, long-sleeved and floor-length dress, embroidered with the date, for the baptism. Perhaps the postponement was because she wanted to finish the dress?

I had a sense of the baptism looming. During Brownie camp, most of the other girls had got up for a midnight feast. It was 9pm and Brown Owl was only pretending that we were being naughty, but I stayed in bed because I wanted to stay worthy for what was to come.

Mormons baptise by immersion. No clam-shell of cold water on the head for us, but a full dunking, head to toe, of a conscious, deciding being. The works. Us kids had our own opinions about it. R, who'd gone just before me, had gone down the steps into the font, put one toe into the water, decided it was too hot, and refused. His mother hissing at him to behave, and him digging his toes into the tiles and shaking his head. No. We'd all had to go back up to the chapel and sing hymns for 20 minutes while the water cooled down and we could go down and have another try.

D, who'd was two years older and an old pro, had had to be done four times because the hem of her dress had kept floating up to the top of the water. Nothing less than full immersion would do. Four times! We reckoned (she reckoned) that there was something intransigent about her sins – she needed the wettest of washings. Nothing was worse than the tale of C, a friend of a friend of a friend, from another congregation in a different area, who'd been baptised at 11 when her mother converted. The dress went see-through in the water and she wasn't wearing a bra. She needed one. Enough said.

Mum had prepared me for the interview in advance of the baptism. Had said the bishop would want to check that I'd understand the Atonement (I still don't) and the gravity of the covenants I was making. Told me not to tell lies, because Heavenly Father would tell him, and he'd know, and pull me up on it right away. I was keyed up, nervous. But instead of sitting in his office, we sat on the steps outside the church and he asked me if I wanted to do it. I said yes. He asked me if I'd brought a towel and clean knickers. I nodded. "Knickers" was horrifically embarrassing – this was my best friend's dad. I couldn't look at him, but I got the seal of approval and we were good to go.

Family links and genealogy are deeply important to most Mormons. I must have known this, because though it wasn't possible for my dad to do the baptism, as was traditional, I'd asked a friend of the family and the man who'd married my parents. I don't remember the water bit. Cold, afterwards, and my mum stripping off my clothes in the changing rooms, and telling me, fiercely, that she was very proud of me. Afterwards, you get your photograph taken, and lots of hand-shaking, and a special tea.

I remember my mum, a few weeks later, telling one of her friends on the phone that I was a "changed girl". I think I had a sense of a slate being wiped clean, and me trying very hard not to dirty it up again. I lasted a fortnight, if that – but I had a little brother and I was only human.

My girl, my best and only girl, will have turned eight years old by the time you read this. Her wrongdoings are legion – but I would say that, I'm her mother. She's also terrifyingly clever. I caught her, some months ago, googling 'IS GOD RIYUL'. We won't be putting her into the water, and I doubt she'll notice anything special about this birthday when she grows up and looks back on her day. Except, if I'm lucky, when she's got eight-year-olds of her own, she'll remember that when it was her birthday, I took her out for ice-cream, and, when no one was looking, hugged her very fiercely and told her how proud I was of her.

'The Friday Gospels', by the Betty Trask award-winning writer, Jenn Ashworth, is published in hardback by Sceptre on Thursday