I need to say right off the bat that I don't write Christian fiction. I apologise if I'm being unfair to authors who work in that genre, but it seems to me that all too often it can result in what is really an evangelistic tract cunningly - or sometimes not so cunningly - disguised as a novel.

The kind of thing where, by the last page, everyone has attended an evangelistic rally, pledged their allegiance to the gospel, and joined a lively church. I'm caricaturing, of course, but there's more than a grain of truth in my description.

So, no I don't write Christian fiction. I do, however, write as someone whose worldview is shaped by the teaching of the Bible. And the more I read and engage with scripture, the more I realise that what I am dealing with is not just 'the Maker's instruction manual' as I've sometimes heard it called.

It does, of course, present us with clear guidelines: the Ten Commandments remain a template for 'the good life' in every place and time, and Jesus' summary of the law as loving God with every fibre of our being and our neighbours calls us to live up to the highest standard.

But what I find in the Bible is not primarily an instruction manual. Rather, it's the great sweeping story of a world created by a loving Creator-God, a world that is broken by sin and selfishness, a world into which Jesus has ushered the reign of God, and a world that will ultimately be renewed. It's a story that challenges me to face life at its darkest and most evil and then invites me to imagine life at its best with creation restored and humanity as God intended it.

So when I write fiction, that big story is always the backdrop against which my little story takes place, always the great drama with which my story must resonate. That means that writing fiction for me, far from being an escape from reality, is actually an exercise in engaging with reality, a way of going deep into truth and of shaping a tale that faces the worst and offers hope for the best.

It means using the power of my God-given imagination to tell a compelling story that will captivate my readers; to draw credible characters and place them in demanding situations; and to raise the big questions of life in a manner that leaves those readers free - and hopefully a little more equipped - to ponder those questions for themselves.

Talking to Calippa Cumberland is my sixth novel, and I've written it especially for Christmas. It follows the life of Lori Bloom, beginning on Christmas Eve 1976 when, as a three and a half year old leaving a department store with her mother, she hears an announcement over the tannoy that a little girl is lost and waiting for her parents at reception.

Lori mistakenly hears the name as Calippa Cumberland and the lost child becomes her imaginary friend. Even in adulthood, Calippa remains a presence in Lori's life, someone to whom she addresses her hopes and fears in the journal she keeps. And we follow Lori through the ups and downs of life and through a succession of Christmas Eves until...well, for that you need to read the book!

It's a story to offer hope that what is lost can be recovered, that lasting friendship can be found, and that Christmas can be all we ever longed for it to be. I hope you'll read it and enjoy it.

"Talking to Calippa Cumberland" (ISBN: 978-1-912726-48-6) by ­­­­­Chick Yuill is published by Instant Apostle and is available from bookshops and online retailers. Fiction, paperback, 224pp, £9.99.