An indulgence is a pious practice which satisfies the requirement of temporal punishment due for mortal sins already forgiven and/or venial sins. Basically, indulgences lessen our sufferings in this life and in Purgatory. There are two kinds, plenary and partial. Plenary indulgences rid one of all the temporal punishment they have accumulated up to that point, whereas partial indulgences only rid one of a bit of temporal punishment. The list of practices which can earn one indulgences can be found in the “Enchiridion of Indulgences.” Here’s a link: catholic.org/clife/prayers/indulgw.php
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