忏悔

repent of one’s sins;atone for sb’s sins;express penitence (or be penitent)for one’s past actions;display (or show,express)remorse for one’s crimes;confess one’s sins
他们相信，不纯洁的灵魂将在炼狱里～自己的罪过。They believe that impure souls may suffer and repent sins in Purgatory.