In stories, characters can be either passive or active:
An active character makes things happen. He has a plan and a goal and places to be. He initiates, produces, and completes.
A passive character has things happen to him. He is caught up, dragged in, swept along. He may be a victim of circumstances or other people, or he may not even know what is going on.
Often, characters change as the story goes on. Frodo, for example, in J.R.R. Tolkien’s Lord Of The Rings. He begins as a passive character, inheriting a strange and disturbing ring from his uncle. Then he is told by Gandalf that he needs to bring the ring to Rivendell. He didn’t ask for the ring, doesn’t want the ring, especially as he finds out more about it. He’s glad to go to Rivendell but he doesn’t fully understand why.
But it isn’t long before Frodo starts becoming an active character. When things don’t go according to plan he is forced to make executive decisions. The journey from The Shire to Rivendell changes him until, at the Council in Rivendell, he volunteers to take the Ring to the Cracks of Doom where it can be destroyed. This time he knows what he’s getting into. This time he makes an active choice.
A character can also go from active to passive. In Stephen Lawhead’s The Sword and The Flame, Quentin goes from an active character, busy with his family, being the king of Mensandor and building a Temple to the Most High God; to a discouraged and disheartened man struggling to deal with the death of a friend and the disappearance of his son. For a short time, he is a passive character, broken and and depressed, before he finds the strength to take action and fight against the evil that is threatening his kingdom.
Character development and change is one way “active and passive” work in a story. Another way is how different characters react to the same circumstances. An aggressive and outgoing character might react to the death of his father by putting on his sword and seeking vengeance, or maybe just looking for a fight. His gentler, more introspective brother might retreat into grief and despair.
Passive characters are not bad, but if they don’t find a purpose and a direction to go, the story will stagnate. For example, in the first draft of my story Moon Shine Red, my main character Ilysa was passive. She reacted to everything, never initiating or thinking for herself. She followed her older brother Isaiah through everything. She was a pair of eyes to see through, not a character in herself.
When I rewrote the story, I realized that Ilysa, to be her own person and a stronger character, needed to make a different choice than her brother, and so, in the beginning of the book, when Isaiah joyfully accepts a new and brilliant life, Ilysa is skeptical and resentful. Although she remains a cautious and mostly passive character, her negative view of what is suddenly the most important thing in Isaiah’s life distinguishes her from him, allowing her to become a person in herself. As she passively allows things to happen to her, circumstances force her to take action and make a choice.
Some things just happen, some things are made to happen. Between the two, they keep the story moving and force every character, whether they react passively or actively, to make choices that lead them into change and development.