The word abyss simply means “a deep hole”—so deep that it seems bottomless or immeasurable. The word is often used in modern contexts to describe the sea.
In the Bible and in Jewish theology, the Abyss is often a metaphorical reference to the place of evil spirits. Sometimes the Abyss is pictured as a deep or bottomless hole in the earth. This is the background for the New Testament usage. The King James Version usually translates the Greek term abyssou as “bottomless pit” (e.g., Revelation 9:2).
In Luke 8, Jesus cast the Legion of demons out of a man, “and they begged Jesus repeatedly not to order them to go into the Abyss” (verse 31). The Abyss is obviously a place that the demons fear and try to avoid.
In Revelation a number of times we see the Abyss as a place of confinement for evil spirits:
Revelation 9:1–3, 11 — “The fifth angel sounded his trumpet, and I saw a star that had fallen from the sky to the earth. The star was given the key to the shaft of the Abyss. When he opened the Abyss, smoke rose from it like the smoke from a gigantic furnace. The sun and sky were darkened by the smoke from the Abyss. And out of the smoke locusts came down on the earth and were given power like that of scorpions of the earth. . . . They had as king over them the angel of the Abyss, whose name in Hebrew is Abaddon and in Greek is Apollyon (that is, Destroyer).”
Revelation 11:7 — “Now when [the two witnesses] have finished their testimony, the beast that comes up from the Abyss will attack them, and overpower and kill them.”
Revelation 20:1–3 — “And I saw an angel coming down out of heaven, having the key to the Abyss and holding in his hand a great chain. He seized the dragon, that ancient serpent, who is the devil, or Satan, and bound him for a thousand years. He threw him into the Abyss, and locked and sealed it over him, to keep him from deceiving the nations anymore until the thousand years were ended.”
In all of these instances, the Abyss is a place for the containment of evil spirits. Many Bible scholars believe that this is the same place referred to in 2 Peter 2:4 as “hell,” where some evil spirits are “in chains of darkness to be held for judgment.” The word hell here is a translation of the Greek tartarus, which can be thought of as the “deepest pit” or the “lowest part of Hades.”
It is clear from Scripture that God has ultimate power over all evil spirits. Some of the demons have been consigned to the Abyss and held captive there, while others seem to be able to move more freely upon the earth. Ultimately, all evil spirits will be consigned to the lake of fire, along with all unbelievers (see Revelation 20:10–15).