The Spirits' Book
Book Four - Hope and Consolation
Chapter II - Future Joys and Sorrows
Duration of Future Atonements
1004. What determines how long a guilty person must atone?
“The length of time required for their betterment. A spirit’s happiness or unhappiness corresponds to their degree of purification. The duration and nature of this suffering depends on the time it takes them to improve. As spirits progress, they refine their views, their torment diminishes and this changes their nature.”