It is clear at the beginning of the book that Crispin has a very literal notion of sin and punishment. He feels tremendously guilty because he feels he has sinned in various ways, and as a result, he is being punished by the events that happen at the beginning of this book, as he is forced to run away and leave the only home he has ever known and to try and protect his life from former friends who would turn him in for money. Note how Crispin, at the end of Chapter Two, lists his various sins:
Then too I had turned from the priest when he had asked me to church. I had broken the curfew also. Why, I'd even stolen church wine to ease my mother's pains before she died. In short, I was certain that God was punishing me.
Crispin therefore is an example of a child with completely innaccurate notions of what sin and crime actually are. He feels that because he has committed what he sees to be "sins," he therefore needs to feel guilty, and his current hardships and sufferings are only because of his sin. He is being punished because of his crimes. It is only through the course of the book and his friendship with Bear that this unhelpful ideas are challenged and successfully debunked.