Revelation 21:8 says this:
But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death. (Revelation 21:8, KJV)
δειλοῖς δὲ καὶ ἀπίστοις καὶ ἐβδελυγμένοις καὶ φονεῦσιν καὶ πόρνοις καὶ φαρμακεῦσιν καὶ εἰδωλολάτραις καὶ πᾶσιν τοῖς ψευδέσιν τὸ μέρος αὐτῶν ἐν τῇ λίμνῃ τῇ καιομένῃ πυρὶ καὶ θείῳ ὅ ἐστιν δεύτερος θάνατος (Revelation 21:8, TR)
The very first word in this list of categories of sinners is "the fearful." What does this really mean? What does the Greek text imply here--that being afraid of anything at all is a sin? or is there a specific kind of fear this may address which would keep someone from going to Heaven?
NOTE: A similar, but different, question is HERE.