Faithless means unbelieving, disbelieving, or lacking fidelity. Scripture uses the term both for those who refuse faith and, in some contexts, for those who prove unfaithful.
Definition
Faithless means without faith, unbelieving, disbelieving, or lacking fidelity. In some contexts it describes unfaithfulness rather than merely refusal to believe.
Biblical Usage
Jesus rebuked a faithless and perverse generation and commanded Thomas not to be faithless but believing. The word may also describe an unfaithful servant and, possibly, the unbelieving.
Historical Background
The term translates the Greek word apistos, meaning without faith. Revised translations distinguish its senses by using unbelieving in some passages and unfaithful in another.
Historical Bible Dictionaries
International Standard Bible Encyclopedia (ISBE)
<p>fath'-les: The translation of apistos, "without faith," having the sense of "unbelieving," "disbelieving." Jesus upbraids the people, "O faithless and perverse generation!" (Mt 17:17; Mr 9:19; Lu 9:41); He says to Thomas, "Be not faithless, but believing" (Joh 20:27); the Revised Version (British and American) adds, "If we are faithless," instead of "believe not" (2Ti 2:13); compare 1Co 7:12-15; 10:27; 14:22,24, etc.; Tit 1:15. In Lu 12:46 apistos has the sense of "unfaithful," so the Revised Version (British and American); perhaps also Re 21:8, "unbelieving."</p>