(1) The writer
As the writer, you need to be writing a story that you care about. Are you writing about something that matters to you, something that’s so important to you that you feel strongly about it? Are you drawing on your own emotional experiences to pour feeling into the story? If writing the story leaves you cold, reading it is more than likely to leave the reader cold as well.
(2) The character
Have you given your character an emotionally loaded goal and motivation? These are the things that the reader can relate to and connect with. Regardless of where or when your story is set, readers relate to the universal human emotions. The character’s goal needs to be specific and urgent, and their motivation for wanting to reach that goal needs to be weighted with emotion, whether it’s positive or negative.
(3) The reader
Are you choosing words with emotional connotations that allow the reader to sense what the character is feeling? Using adjectives and adverbs to describe how your character feels comes across as ‘telling’, asking the reader to take the author at their word, without ‘showing’ what is going on with the character. Choosing verbs with emotional connotations is far more effective – don’t let your characters simply ‘walk’, instead, have your happy character skip, while your anxious character paces and your relaxed character ambles.
Making sure that you address all three of these elements in your writing will help you build that emotional connection between your character and your reader, getting the reader to care about the character, to root for them, to need to know how things work out – so that their eyes race across the page and they simply can’t put the book down.