Moreover, we read later that death itself, along with Hades, is cast into this same lake of fire and sulfur.

28. What is the lake of fire and sulfur, and how is it unlike death, Hades, and the abyss?

²⁸ In harmony with this, the Bible itself explains the meaning of the lake of fire and sulfur: “This means the second death, the lake of fire.” (Revelation 20:14) It is clearly the same as the Gehenna that Jesus spoke of, a place where the wicked remain destroyed, not tortured forever. (Matthew 10:28) It is complete, utter destruction without hope of a resurrection. Thus, while there are keys for death, Hades, and the abyss, there is no mention of a key for opening the lake of fire and sulfur. (Revelation 1:18; 20:1) It will never release its captives.​—Compare Mark 9:43-47.