A writer's heart must beat. A reader's heart must hear it.
A writer's voice is not character alone, it is not style alone; it is far more. A writer's voice line the stroke of an artist's brush- is the thumbprint of her whole person- her idea, wit, humor, passions, rhythms.
The passion for the story is the wind in your narrative sails. Begin at the heart. We must hear the heartbeat of the story. Love your characters into existence.