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:
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.
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:
You can learn much more about these two places in our Revelation course.