What is it?
Q. The Bible tells us we die once and then comes judgment. So why does it speak of the "second death" in the book of Revelation?
We Die Once
In Hebrews 9:27 we find the verse:
"it is appointed for men to die once and after this comes judgment."
Second Death References
Yet, a "second death" is referenced in Revelation 2:11, 20:6, 20:14 and 21:8.
"He who overcomes will not be hurt by the second death" (Rev 2:11).
"Blessed and holy is the one who has a part in the first resurrection; over these the second death has no power…" (Rev 20:6).
"Then death and Hades were thrown into the lake of fire. This is the second death, the lake of fire" (Rev 20:14).
"But for the cowardly and unbelieving and abominable and murderers and immoral persons and sorcerers and idolaters and all liars, their part will be in the lake that burns with fire and brimstone, which is the second death" (Rev 21:8).
Although not a very popular concept, punishment by fire "is prominent in both Biblical and non-Biblical Jewish writings (e.g., 1 Enoch 54:1)" (Zondervan Study Bible]). We can't really dismiss it if we are biblical believers - no matter how much we wish we could.
Most of our study-bible commentaries note that the first death is just physical. It is when we die on earth and are buried or cremated in traditional ways.
The believer who puts faith in the lordship and redemptive powers of Jesus Christ will never experience the second death. At death he goes to be with the Lord and awaits resurrection of the body when the rapture occurs (Philippians 3:20-21).
"For our citizenship is in heaven, from which we also eagerly wait for the Savior, the Lord Jesus Christ, who will transform our lowly body that it may be conformed to His glorious body, according to the working by which He is able even to subdue all things to Himself" (NKJV).
But, once unbelievers are all resurrected to be judged, the second death is the "everlasting death of torment in the lake of fire for those who face the great white throne judgment…" (NKJV Study Bible 2007, 2641).
It is a "spiritual and eternal" death and "could exist outside the created universe as we know it, outside of space and time, and be presently unoccupied" (MacArthur Study Bible 1996, 2021).
To help us picture this scenario, science fiction comes to our rescue again. We need only see the habitat of the "Ori" in Stargate who occupy places that look like a burning lake of fire. (e.g.The Ark of Truth). An earthly example might be the steaming pits from the heart of an erupting volcano.
A Habitat for Evil Beings
Regardless, it is not a pleasant place. It seems that eternal judgment will bring unbelievers, Satan and the devil's angels into an eternal, fiery existence from which they cannot escape.
It is worthwhile to note that Jesus said this place was originally prepared for the devil and his angels (Matt 25:41). But, because of his horrendous rebellion, somewhere along the line mankind so completely "blew it" that humans earned a place there, too. If we are honest with ourselves, we instinctively know it to be true.
MacArthur Study Bible, NKJV. 1996. Nashville, TN: Nelson.
NKJV Study Bible, large print. 2007. Nashville, TN: Nelson.
Stargate: The ark of truth. 2008. (DVD). MGM Studios.
Zondervan Study Bible, KJV, large print. 2002. Grand Rapids, MI: Zondervan.
Images of Lake of Fire from wisdomintorah.com.