When I was a child my father trained me to imagine my hands were on fire, so if I was ever caught in a snowstorm I could stay alive. (An immigrant who had crossed many oceans, he was obsessed with survival.) He taught me to close my eyes, clasp my hands and picture them bursting into flames. After I'd been concentrating for a few minutes he would touch my hands to check their progress. Although I never burned him (our tacit goal), by the end of the training, I could will my hands to be warmer.
It occurs to me now that before I pictured the fire, I would picture the snowstorm. I would place myself in the scene. The thought of cold blasts of snow all around me, combined with a fear of death, made my need for the fire more pressing. It made the image of my hands in a red orange blaze (the image that raised my body temperature) easier to conjure. We lived in California. I had only seen snow in pictures. But that didn't matter. What mattered was the relationship between high stakes and imagination.
A similar principle applies to writing fiction. There can be no fire (no action, no story) without snow (without threat, without sacrifice). You must put your characters in harm's way, you must allow them to get caught in the snowstorm. Another way to say this is you must put yourself at risk. You must make the world believable—not to the person checking your progress (the reader) but to you (the writer), the one trying to survive in the snow. If the snow is real to you, the reader will feel a chill. If the fire is real to you, the reader will be warmed by it. You must change your own body temperature in order to change the reader's.
Writing a convincing story is like setting fire to your own hands using only the match of your imagination. Success seems unlikely but it is possible. In both scenarios, no one really goes anywhere and yet in both scenarios, with practice and concentration, hearts beat faster and bodies grow warmer. If you want your story to catch fire, raise the stakes. Go walking in the snow. Get cold. Get frostbitten. Make the fire necessary. Then make the fire.