I declare, monks [dhammafarers], that actions (kamma) willed, performed and accumulated, will not become extinct as long as their results have not been experienced, be it in this life, in the next life or in future lives. And as long as these results of actions willed, performed and accumulated, have not been experienced, there will be no end to suffering.
-words of Gautama Buddha
Parallel saying in contemporary Christian tradition:
I heard a priest once say the fires of hell and the pain of purgatory weren't literal fire, but the burning pain of regret around unhealed or unresolved harmful actions.