A.T. Robertson Commentary Revelation 21:8

"But for the fearful, and unbelieving, and abominable, and murderers, and fornicators, and sorcerers, and idolaters, and all liars, their part [shall be] in the lake that burneth with fire and brimstone; which is the second death." — Revelation 21:8 (ASV)

Their part shall be (το μερος αυτων). In contrast to the state of the blessed (verses 3-7) the state of "those who have disfranchised themselves from the Kingdom of God" (Charles) is given. They are with Satan and the two beasts, and are the same with those not in the book of life (20:15) in the lake of fire and brimstone (19:20; 20:10,14f.), that is the second death (2:11; 20:6,14). See also 14:10. There are eight epithets here used which apply to various sections of this direful list of the doomed and the damned, all in the dative (case of personal interest).

For the fearful (τοις δειλοις). Old word (from δειδω, to fear) for the cowardly, who recanted under persecution, in N.T. only here, Matthew 8:26; Mr 4:40.

Unbelieving (απιστοις). "Faithless," "untrustworthy," in contrast with Christ "ο πιστος" (1:5). Cf. 2:10,13; 3:14; 17:14. Disloyalty is close kin to cowardice.

Abominable (εβδελυγμενοις). Perfect passive participle of βδελυσσω, old verb, in N.T. only here and Ro 2:22, common in LXX, to pollute (Exodus 5:21). Those who have become defiled by the impurities of emperor-worship (7:4f.; 21:27; Romans 2:22; Titus 1:16).

Murderers (φονευσιν). As a matter of course and all too common always (Romans 1:29; Revelation 9:21).

Fornicators (πορνοις). Again all too common always, then and now (1 Corinthians 5:10; 1 Timothy 1:9f.). These two crimes often go together.

Sorcerers (φαρμακοις). Old word, in N.T. only here and 22:15. Closely connected with idolatry and magic (9:21; 13:13f.).

Idolaters (ειδωλολατραις). See 1 Corinthians 5:10f.; 10:7; Ephesians 5:5; Revelation 22:15. With a powerful grip on men's lives then and now.

All liars (πασ τοις ψευδεσιν). Repeated in 22:15 and stigmatized often (2:2; 3:9; 14:5; 21:8,27; 22:15). Not a "light" sin.