In doing a study of the Lake of fire in Revelation one discovers that the fires are a purifying fire. The word used to describe the fire is theion and means:
1)brimstone
A)divine incense, because burning brimstone was regarded as having power to purify, and to ward off disease
blueletterbible.org/lang/Lexicon/Lexicon.cfm?strongs=G2303&t=KJV
This has lead some to say that those who enter the fire are purified. But a better way of looking at it is to say that God’s creation is purified as the sheep are separated from the goats. Kolasis means to prune or cut off. When Christ says depart from me the goats are separated from “all mankind”. All are salted with fire as the sheep are separated from the goats. The pruning takes place so that the body can grow better as the “whole world” is purified by the purging fires. This is the correction that takes place as the goats are separated from God’s mercy. All forms of mercy (common and saving) are removed from the hearts of the goats. As a result their hearts harden. Because of harden hearts they don’t want God and hate Him. The longer their hearts are separated from all mercy the harder it becomes and the more wicked it becomes. The torment they receive is calibrated just right to restrain them from harming each other in the lake of fire. Thus we see God’s severity, kindness and protective love even on those who are tormented in the lake of fire and separated from His mercy.