certain
sure
arrogant
assured
believing
cocksure
confident
decided
determined
devout
dogmatic
doubtless
faithful
fideistic
hubristic
impressed with
overconfident
oversure
overweening
persuaded
pietistic
pious
pistic
poised
pompous
positive
proud
reassured
satisfied
secure
self-assured
self-confident
self-important
self-reliant
sold on
unafraid
under the impression
undoubtful
undoubting
unfaltering
unhesitating
unwavering
evinced
minced
unconvinced
winced