Compare Mark 9:42-48 with Isaiah 66:24. How do you understand the expression “their worm does not die” (Mark 9:48, NKJV)?

 Some interpret the singular noun “worm” (Mark 9:48) as an allusion to the supposed disembodied soul or spirit of the wicked that, after death, flies into hell, where it never dies and suffers eternal torment.

 But this interpretation does not reflect the biblical notion of unconscious death; it also ignores the Old Testament background of this passage. Actually, “the singular ‘the worm’ is used generically for ‘the worms’ — it does not mean a single worm. The reference is to worms which feed upon decaying bodies.” — Robert G. Bratcher and Eugene A. Nida, A Translator’s Handbook on the Gospel of Mark (London: United Bible Societies, 1961), p. 304.

 In Mark 9:48 Jesus is quoting Isaiah 66:24, which reads, “And they will go out and look on the dead bodies of those who rebelled against me; the worms that eat them will not die, the fire that burns them will not be quenched, and they will be loathsome to all mankind” (NIV).

 This frightening metaphorical scene portrays a battlefield with God’s enemies dead on the ground and being destroyed. The bodies not consumed by fire are decomposed by worms, or perhaps first by worms and then by fire. Either way, there is no reference whatsoever to any alleged soul escaping the destruction of the body and flying into hell.

 But what about the “worms” that never die? The metaphoric language of Isaiah 66:24 (quoted in Mark 9:48) does not imply that those worms are immortal. (Immortal worms?) The emphasis is that the worms do not leave their destructive task incomplete. In other words, they continue to devour the bodies of the wicked until these bodies are destroyed. By contrast, God’s faithful children will joyfully abide in “the new heavens and the new earth” and worship God in His very presence (Isa. 66:22, 23, NIV). With such contrasting destinies in mind, no wonder that Jesus stated that it would be far better for someone to enter the kingdom of God without a crucial part of his or her body — without a hand, or foot, or even an eye — than to have a perfect body that will be destroyed by worms and fire (Mark 9:42-48).