
Your story's characters have to support your theme. That does not mean the characters should follow what the story needs them to do. They should always act in the spirit of their own motivations. But include characters that are vital to the storyline. Be also aware that complex characters can have many motivations. Some of those motivations will be competing ones.
When writing about character activities, make sure they do what they want. They should not act as the author wants. That's enough for today. Next time I will go into character voice and other things related to dialog.