Writers spend a lot of time on character and plot, which of course are very important, but remember that your story will be boring without CONFLICT. Conflict doesn’t just bring excitement to the pages. Conflict brings characters to life.
Think about this. We all make snap decisions about people based on appearance and background information, but it’s not until we see people in action that we learn who they are.
Let’s say you’re in high school, sitting in a classroom, and there’s a new girl in class. 
She’s beautiful, busty, looks like a model. You have some background on her, too, because kids gossip. You know her parents are rich. She wears designer clothes. She moved here from California. She was a cheerleader.
So you have a picture of her, right? You have your first impressions of her. Maybe you think she’s snobby, privileged, stuck on herself.
Now let’s put her in scene and introduce some conflict and see what happens.
She’s there in the classroom. A student in the back pulls out a gun and starts waving it around. There’s chaos. Everyone’s screaming and ducking for cover. Everyone’s crouched beneath their desks, including this girl—and the kid with the gun is walking up and down between the rows. When he passes the girl, she puts out her foot and trips him. He falls and the gun goes flying. Then she tackles him.
Has your impression of her changed?
What if, instead of putting her foot out, she screams hysterically and won’t shut up? What if she closes her eyes and prays. What if she stands up and tries to talk the guy down?
With each of these scenarios, we change the girl’s character. Conflict—and how your characters react to conflict—is what brings the characters to life.