What's the difference between the Bottomless Pit and the Lake of Fire?
The Bible has much to say concerning the destination of men's souls at death and the dwelling place for demons. First, the Bible teaches in 1Corinthians 15 that our existence is one partly of flesh and partly of spirit. The flesh of our bodies is destined to end at our physical death, but our spirit is eternal. Therefore, when our physical body dies, our spirit must go to a new place.
Jesus teaches in Luke 16 that God has prepared a place of confinement for the souls of those who die without faith. The place is called Hades, which we call Hell. This place holds the souls of all men who have died without faith in God's promises (i.e., unbelievers), and these persons will remain in soul-form in Hades until the day of their judgment. That day is called the Great White Throne Judgment, which is described in Revelation 20:
Rev. 20:12 And I saw the dead, the great and the small, standing before the throne, and books were opened; and another book was opened, which is the book of life; and the dead were judged from the things which were written in the books, according to their deeds.
Rev. 20:13 And the sea gave up the dead which were in it, and death and Hades gave up the dead which were in them; and they were judged, every one of them according to their deeds.
Rev. 20:14 Then death and Hades were thrown into the lake of fire. This is the second death, the lake of fire.
Rev. 20:15 And if anyone’s name was not found written in the book of life, he was thrown into the lake of fire.
Once the Great White Throne Judgment concludes, the souls of all unbelievers will be condemned for their sin and cast into the Lake of Fire, which is their final eternal home. Jude 7 speaks of this eternal home.
Jude 7 just as Sodom and Gomorrah and the cities around them, since they in the same way as these indulged in gross immorality and went after strange flesh, are exhibited as an example in undergoing the punishment of eternal fire.
Finally, the bottomless pit or the abyss is a place where God keeps demons captive until they receive their judgment and punishment, also in the Lake of Fire. Luke 8 references this holding place:
Luke 8:30 And Jesus asked him, “What is your name?” And he said, “ Legion”; for many demons had entered him.
Luke 8:31 They were imploring Him not to command them to go away into the abyss.
You can learn much more about these two places in our Revelation course.