Now let's consider this "lake of fire", and see if it even exists eternally in context:
Please read these texts together, what do you see [ignore for a moment the chapter division]?
Revelation 20:14 - And death and hell were cast into the lake of fire. This is the second death.
Revelation 20:15 - And whosoever was not found written in the book of life was cast into the lake of fire.
Revelation 21:1 - And I saw a new heaven and a new earth: for the first heaven and the first earth were passed away; and there was no more sea.
Revelation 21:2 - And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband.
Revelation 21:3 - And I heard a great voice out of heaven saying, Behold, the tabernacle of God is with men, and he will dwell with them, and they shall be his people, and God himself shall be with them, and be their God.
Revelation 21:4 - And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away.
Revelation 21:5 - And he that sat upon the throne said, Behold, I make all things new. And he said unto me, Write: for these words are true and faithful.
While Revelation 21:1 states that in the New Heaven and New Earth there will be no more "sea" [water, the vast chasm of] as such we have now [due to the flood of Noah], with restless waves, separating friends and loved ones, but instead broad rivers, etc, as per:
Isaiah 33:14 - The sinners in Zion are afraid; fearfulness hath surprised the hypocrites. Who among us shall dwell with the devouring fire? who among us shall dwell with everlasting burnings?
Isaiah 33:15 - He that walketh righteously, and speaketh uprightly; he that despiseth the gain of oppressions, that shaketh his hands from holding of bribes, that stoppeth his ears from hearing of blood, and shutteth his eyes from seeing evil;
Isaiah 33:16 - He shall dwell on high: his place of defence shall be the munitions of rocks: bread shall be given him; his waters shall be sure.
Isaiah 33:17 - Thine eyes shall see the king in his beauty: they shall behold the land that is very far off.
Isaiah 33:18 - Thine heart shall meditate terror. Where is the scribe? where is the receiver? where is he that counted the towers?
Isaiah 33:19 - Thou shalt not see a fierce people, a people of a deeper speech than thou canst perceive; of a stammering tongue, that thou canst not understand.
Isaiah 33:20 - Look upon Zion, the city of our solemnities: thine eyes shall see Jerusalem a quiet habitation, a tabernacle that shall not be taken down; not one of the stakes thereof shall ever be removed, neither shall any of the cords thereof be broken.
Isaiah 33:21 - But there the glorious LORD will be unto us a place of broad rivers and streams; wherein shall go no galley with oars, neither shall gallant ship pass thereby.
[see also Ezekiel 47:1-6]
Isaiah 33:22 - For the LORD is our judge, the LORD is our lawgiver, the LORD is our king; he will save us.
Isaiah 33:23 - Thy tacklings are loosed; they could not well strengthen their mast, they could not spread the sail: then is the prey of a great spoil divided; the lame take the prey.
Isaiah 33:24 - And the inhabitant shall not say, I am sick: the people that dwell therein shall be forgiven their iniquity.
The text also reveals that the "lake of fire", even the fiery "sea" will have passed away also, for it was upon this old earth, look again [ignore the chapter break for a moment, just read it straight through]:
Revelation 20:14 - And death and hell were cast into the lake of fire. This is the second death.
Revelation 20:15 - And whosoever was not found written in the book of life was cast into the lake of fire.
Revelation 21:1 - And I saw a new heaven and a new earth: for the first heaven and the first earth were passed away; and there was no more sea.
In scripture, a "Sea" = "Lake" [whether of water, fire, etc]:
Luke 5:1 - "the lake of Gennesaret" [see "sea of Chinnereth" [Numbers 34:11], [see also "Chinnereth" [Deuteronomy 3:17; Joshua 19:35]] or "sea of Chinneroth" [Joshua 12:3], or "of Gennesaret" [Matthew 14:34; Mark 6:53]; Matthew 8:27; Mark 4:39,41 uses the word "sea" and John 6:1 says, "sea of Galilee, which is the sea of Tiberias".
The very word "lake" in the Koine Greek in Revelation 20:14,15 is λιμνην [limnen].
G3041 [only used in the Koine Greek of the NT, I didn't find it in the (so-called) LXX either]
λίμνη limnē
Total Occurrences: 10
lake, 10
Luke 5:1-2 (2), 8:22-23 (2),33;
Revelation 19:20, 20:10,14-15 (2), 21:8
See also the alternate word for "sea":
G2281 [its also in the (so-called) LXX, in the very places of the "sea of Chinnereth" [Numbers 34:11,12 (so-called) [LXX], etc]
θάλασσα thalassa
Total Occurrences: 95
sea, 93
Mat_4:15, Mat_4:18 (2), Mat_8:24, Mat_8:26-27 (2), Mat_8:32, Mat_13:1, Mat_13:47, Mat_14:24-26 (3), Mat_15:29, Mat_17:27, Mat_18:6, Mat_21:21, Mar_1:15-16 (3), Mar_2:13, Mar_3:7, Mar_4:1 (3), Mar_4:39, Mar_4:41, Mar_5:1, Mar_5:13 (2), Mar_5:21, Mar_6:47-49 (3), Mar_7:31, Mar_9:42, Mar_11:23, Luk_17:2, Luk_17:6, Luk_21:25, Joh_6:1 (2), Joh_6:16-19 (4), Joh_6:22, Joh_6:25, Joh_21:1, Joh_21:7, Act_4:24, Act_7:36, Act_10:6, Act_10:32, Act_14:15, Act_17:14, Act_27:30, Act_27:38, Act_27:40, Act_28:4, Rom_9:27, 1Co_10:1-2 (2), 2Co_11:26, Heb_11:12, Heb_11:29, Jas_1:6, Jud_1:13, Rev_4:6, Rev_5:13, Rev_7:1-3 (3), Rev_8:8-9 (3), Rev_10:2, Rev_10:5-6 (2), Rev_10:8, Rev_12:12, Rev_13:1 (2), Rev_14:7, Rev_16:2-3 (4), Rev_18:17, Rev_18:19, Rev_18:21, Rev_20:8, Rev_20:13, Rev_21:1
red [sea], 2
Act_7:36, Heb_11:29