You mean you build your characters according to the story, not the story around the characters?
Er... Good question!
The honest answer is 'it depends'. Most supporting characters, probably yes. And that can be dangerous. Characters need their own life. Where does that life come from? It has to come from yourself. You have to be able to imagine yourself acting like that, even if in real life you never would.
You are a Christian. How has this influenced you?
It's the other way around. The things that prompt me to write about moral confusion, duty and sacrifice also prompt me to be a Christian. What tempts us? What is the Fall like? That's why my books resonate with these ideas. But I don't write to persuade. I ask the questions that interest me.
What's the next book about?
There are various things in various stages of making. There's a third Muddle. There's a swashbuckling comic strip adventure I wrote for the Phoenix called Red Jack which is begging to be made into a novel.
But the main effort at the moment is a fantasy horror featuring dopplegangers. Suppose you could divide yourself, and place everything that you didn't like about yourself into an exact copy of you. You could be anything you always wanted to be. You could be happy, and there would be someone who looked exactly like you going around being sad all the time. You could be brave, and there would be a double of you who was always quaking with fear.
So... What if you chose to be good?