First you said
It is not in the bible.
Then you refer to an apologist tract discussing places where it is in the Bible. Unfortunately, your apologist takes snippets of verses, ignoring parts that don't fit his narrative:
At Revelation 20:1-3 we note, "And I saw an angel come down from heaven, having the key of the bottomless pit and shut him up, and set a seal upon him...". Here we have the devil "jailed" in the bottomless pit unable to "get out".
Let's read all of verses 1-3:
Then I saw an angel come down from heaven with the key of the Abyss in his hand and an enormous chain. [2] He overpowered the dragon, that primevial serpent which is the devil and satan, and chained him up for a thousand years. [3] He hurled him into the Abyss and shut the entrance and sealed it over him, to make sure he would not lead the nations astray again until the thousand years had passed. At the end of that time he must be released, but only for a short while.
Continue reading this chapter. The devil returns, and we learn his fate in verses 9 and 10:
They [Gog and Magog] came swarming over the entire country and beseiged the camp of the saints, which is the beloved City. But fire rained down on them from heaven and consumed them. [10] Then the devil, who led them astray, was hurled into the lake of fire and sulphur, where the beast and the false prophet are, and their torture will not come to an end, day or night, for ever and ever.
The lake of fire is a place of eternal torture. The same "burning lake" is the place of "second death" for those who are not recorded in the book of life, as we see in verses 14-15:
Death and Hades were emptied of the dead that were in them; and every one was judged as his deeds deserved. Then Death and Hades were hurled into the burning lake. This burning lake is the second death; [15] and anybody whose name could not be found written in the book of life was hurled into the burning lake
Thus the second death is tied to eternal torture, in that same lake of fire. The torture is real, but beyond human reckoning. This is not the fire of our physical world, but being consumed by fire is as close as human words of the time could describe the worst of all possible torments: eternal separation from god's presence. Thus the biblical phrase "hellfire": an imperfect, frightful, human description of an unimaginable spiritual fate.
It would make Jehovah unfair, by his own standards, and not a God of mercy and love.
Does it? Look again at verse 14, "judged as his deeds deserved". Those who chose the Lord's way will be in his presence, and those who chose to live without the Lord also have their wish granted. It is our choice to make, not God's, judgement is checking the record to see what our choice was. There is nothing "unfair" or "unloving" about impartial judgement. That we sinners even have a chance to be in his presence is the ultimate expression of God's mercy, grace and love.
With that, at this late hour, let us agree that we don't agree and return to the main topic of this thread.