Heya Leon, howya doing?
This is because the Bible says it is so:
Revelation 20:14Then death and Hades were thrown into the lake of
fire. The lake of
fire is the second death.
Revelation 20:15If anyone's name was not found written in the book of life, he was thrown into the lake of
fire.
May I ask, what do you base this on? How do you know the attributes of the spiritual body, and how do you know the nature of spiritual fire, or if you don't believe it is spiritual fire, how do you know that fire will not harm these bodies?
This is correct, which is why some Christians do not believe that Hell is eternal, in the sense that you are conscious and it lasts forever, Hell is finite. You are tossed into the lake of fire, and your spiritual body is destroyed, and that's it. The second death.
I'm currently trying to decide which version I believe, as both can be reasoned with Biblically, I'm just not sure.
May I ask, why have you asked this question originally?
All the best!
Digit