Holy Master Ziguang Shang Shi gave a speech on why to help beings in Hells to extinguish or reduce their sin:
The beings in Hells are always in the darkness. It opens for them to return to the saha world this month.
Why is it call "Extinguish/Reduce Sin?" Because when living in the world, people will have this or that wrong, and make this or that mistake. It is called "sin" in Buddhism. The weight of sin determines how long they have to stay in Hells and how much suffer they have to endure. People might not understand all reasons behind. Those who have understood, they will make less wrongs, and will accumulate more merits, do good deeds instead of doing bad deeds.
Event: Extinguish/Reduce Sin Dharma Convention
Venue: Holy Mountain Buddha Land Great Hero Hall
Read More:
How Much Force Needed to Change the Karma