dubious
agnostic
ambiguous
capricious
chancy
changeable
creedless
dicey
disbelieving
doubting
equivocal
erratic
faithless
fickle
heretical
hesitant
hesitating
incalculable
incredulous
indecisive
indemonstrable
irreligious
irresolute
minimifidian
nonbelieving
nullifidian
polysemous
repudiative
skeptical
touch-and-go
unaccountable
unbelieving
uncertain
unconfident
unconfirmable
unconverted
undivinable
unforeseeable
unpersuaded
unpredictable
unprovable
unsure
unverifiable
variable
wavering
whimsical
without faith
abashed
bemused
different
discomfit
dumbfounded
ill-at-ease
inadmissible
oblivious
unaccounted
uncalled
undecided
unfitted
unhurt
unimpressed
uninformative
uninterested
unmanageable
unoffended
unremarkable
unsurprised
untenanted
convinced
evinced
minced
winced