Unbelief - Vine's Expository Dictionary of New Testament Words
Unbelief
[ 1,,G570, apistia ]unbelief" 12 times, but See BELIEF, C, Note
(2) for references.
[ 2,,G543, apeitheta ]
is always rendered "disobedience" in the RV; in Romans 11:30, Romans 11:32 and Hebrews 4:6, Hebrews 4:11, AV, "unbelief." See DISOBEDIENCE, A, No. 1.