I'm not so sure you truly understanding it either, simply because the future "lake of fire" is a heavenly dimension type of event, though it will be upon this earth. Lord Jesus compared it to the OT Valley of Hinnom, which was a place outside the walls of Jerusalem that served as a perpetual burning garbage pit, and where the rebellious sacrificed their sons and daughters in the fire. He used that (geena) symbolically for the "lake of fire". But one must go to the Greek and translate the word "hell" in the NT to discover when He was pointing to it. It was also called Tophet, which Isaiah 30:33 uses Tophet to point the future destruction of Satan in that "lake of fire".Because the symbolic lake of fire is so misunderstood, we can be very thankful God chose to define it in both places where it occurs in His word. It means the second death, or permanent death sir. Everything cast into it is gone forever. Although they are not literally burned, such as you cannot burn death and hell, but at that point death is no more Rev 21:4, so fittingly hell is no longer necessary as no one goes there to await a resurrection any more, and death has ceased to exist.
GOD can... destroy one's spirit with soul. Man cannot (Matthew 10:28). And the heavenly dimension "lake of fire" event for the end of Christ's future "thousand years" reign will accomplish it, called the "second death". That "second death" is the destruction of one's spirit with soul, not their flesh.
HINNOM
(lamentation), Valley of, otherwise called "the valley of the son" or "chi
ldren of Hinnom," a deep and narrow ravine, with steep, rocky sides, to the south and west of Jerusalem, separating Mount Zion to the north from the "hill of evil counsel," and the sloping rocky plateau of the "plain of Rephaim" to the south. The earliest mention of the valley of Hinnom is in Josh 15:8; 18:16, where the boundary line between the tribes of Judah and Benjamin is described as passing along the bed of the ravine. On the southern brow, overlooking the valley at its eastern extremity Solomon erected high places for Molech, 1 Kings 11:7, whose horrid rites were revived from time to time in the same vicinity the later idolatrous kings. Ahaz and Manasseh made their children "pass through the fire" in this valley, 2 Kings 16:3; 2 Chron 28:3; 33:6, and the fiendish custom of infant sacrifice to the fire-gods seems to have been kept up in Tophet, which was another name for this place. To put an end to these abominations the place was polluted by Josiah, who renders it ceremonially unclean by spreading over it human bones and other corruptions, 2 Kings 23:10,13,14; 2 Chron 34:4,5, from which time it appears to have become the common cesspool of the city, into which sewage was conducted, to be carried off by the waters of the Kidron. From its ceremonial defilement, and from the detested and abominable fire of Molech, if not from the supposed ever-burning funeral piles, the later Jews applied the name of this valley — Ge Hinnom, Gehenna (land of Hinnom) — to denote the place of eternal torment. In this sense the word is used by our Lord. Matt 5:29; 10:28; 23:15; Mark 9:43; Luke 12:5.
(from Smith's Bible Dictionary, PC Study Bible formatted electronic database Copyright © 2003, 2006 by Biblesoft, Inc. All rights reserved.)