Some people try to punish themselves for their sins. They do not stand on the promises of forgiveness and Christ's propitiation.
"Many years ago, a father and his daughter were walking through the grass on the Canadian prairie. In the distance, they saw a prairie fire, and they realized that it would soon engulf them.
The father knew there was only one way of escape: They would quickly begin a fire right where they were and burn a large patch of grass. When the huge fire drew near, they then would stand on the section that had already burned.
When the flames did approach them, the girl was terrified but her father assured her, 'The flames can't get to us. We are standing where the fire has already been.'"
- Erwin Lutzer, Failure, The Back Door to Success.