There are a lot of elements that have to come together in order to create a good story. You have to have compelling characters, you have to have a plot that actually goes somewhere, you have to have scenes and events that unfold at a quick pace, and you have to infuse your story with emotion. This may be the most important part of the story. If you don't get your readers emotionally involved, you won't get a story that works. It's like baking bread but forgetting the yeast. Without the yeast, bread won't rise. Without the emotions, your story will fall flat.
Think about all the stories you've ever read. Which were your favorites? Which stand out most in your head? Which ones can you not forget about? Better yet, which ones had your blood pumping and your heart racing? Which ones left you peeking behind your shoulder looking for the villain? Which ones left you sobbing in a ball on your couch while the characters dealt with a loss of some kind? I'd be willing to bet the ones that stand out are the ones that got you emotionally entangled with the story.
When you're a writer, it's extremely important to remember emotions. Look at the difference in these scenes by adding a few emotions....
"You're leaving me?" John asked.
"Yes," Anna confirmed.
Anna glanced away, "Well, I'm looking for different things than you are. The life I have with you isn't the life I want."
John was silent. "Oh," he finally said. "Then I can't fight that."
"No. I'm sorry John." Anna turned and walked away.
All John could do was watch her go.
Okay, that's a scene. You get the picture. You feel kinda bad for John, but you don't really get the depth of it. So, here it is again with a little more emotion....
"You're leaving me?" John asked. The words felt like a vise, squeezing his heart. His chest throbbed painfully.
"Yes," Anna confirmed, looking away. She couldn't look at him, knowing she was breaking him.
"Why?" he choked.
She sighed, "I'm looking for different things than you are, John. The life I have with you isn't the life I want."
John was silent, heartbroken. His chest constricted as he fought back the pain that threatened to crush his heart. He couldn't make her stay. He couldn't change anything to make it better for her. His hands were tied. "Oh," he finally managed. "Then I can't fight that."
"No," she smiled softly, tears in her eyes, and touched his arm. "I'm sorry John. I really am." She turned and walked away, leaving John staring after her, broken and helpless.
So that was scene two. In my opinion, you feel more for John after reading scene two. Of course, sometimes the simple scenes work better. But, still, emotion. You have to get emotion in a scene otherwise it just won't work! So the question that comes up is obvious: how do you get emotion in a scene? In my writing I've found that the best way to do it is to put myself in the character's shoes, try to feel exactly what they're feeling, and then put that on paper. I visualize. I close my eyes and imagine myself as the character. How would she feel physically and emotionally? How would she react? I've found that this technique really helps me discover what emotions and feelings need to be in the scene. This works so well, in fact, that the scenes I find easiest to write are those that are emotionally charged. If my character is sad, scared, lost, upset, or any reaction that draws out strong emotions, I'll write the whole thing, thousands of words, and it'll take me hardly any time at all. Without the emotions, I drag through a scene trying to make it work. Emotions are key both for you and your reader!