I believe the lake of fire will always exist, should we choose to return to our sin.
I think no one who loves sin will enter God's kingdom. The Lake of Fire is OUR EARTH, that's why Peter describes it as burning via all of the elements on fire, its not at the Second Coming, but when Satan is loosed for a little season, then deceives the nations, and then God sets this whole earth on fire, "He makes fire come down from above" on the wicked.
Rev. 20:9 And they went up on the breadth of the earth, and compassed the camp of the saints about, and the beloved city:
and fire came down from God out of heaven, and devoured them.10 And
the devil that deceived them was cast into the lake of fire and brimstone, where the beast and the false prophet are, and shall be tormented day and night for ever and ever.
Then we see the New Heaven and New Earth in Rev. 21, so it all fits together IMHO. This earth has been won by Satan, in a sorta joke on him, Satan wins his prized possession. This earth will be set ablaze, and is going to be Hell, or where the Presence of God does not exist.
NOTICE:
Rev. 20:11 And I saw a great white throne, and him that sat on it,
from whose face the earth and the heaven fled away; and there was found no place for them.
I have always stated God does not condemn us to hell, he gave us a free will to chose our own hearts desire, so if we go to hell we chose to follow Satan and to love Evil, over God. Thus Hell is just us living outside the presence of God Almighty.
Now looking at the above, it hit me, the THEM is the old Earth and Heaven, God will no longer abide in them, we will gain a New Heaven and New Earth, but this former Universe/Earth will be set ablaze. Sin and evil will thus be contained in this old universe for evermore.