un-be-lev'-er: This word follows closely the lines of "unbelief" (which see) in its relation to originals. Once only (Ac 14:2) it represents the participle apeithountes, "disobeying (ones)." Elsewhere (nine cases) it represents apistos, "faithless," "without faith." In six of these passages (all in 1 and 2 Corinthians) it denotes the unconverted pagan as distinguished from the convert. In the other passages (Lu 12:46; Tit 1:15; Re 21:8) the reference is to the unbelief which comes of moral resistance to God.
The International Standard Bible Encyclopedia
Unbeliever
The International Standard Bible Encyclopedia, James Orr (1915). Public domain, from the CrossWire SWORD module.