incredulous

adjectives

not disposed or willing to believe; unbelieving
incredulous
is derived from
incredulity
antonym
credulous
is similar to
denying or questioning the tenets of especially a religion
"a skeptical approach to the nature of miracles"
disbelieving, sceptical, skeptical, unbelieving
see also
beyond belief or understanding
"at incredible speed"; "the book's plot is simply incredible"
incredible, unbelievable
see also
having or showing distrust
"a man of distrustful nature"; "my experience...in other fields of law has made me distrustful of rules of thumb generally"- B.N.Cardozo; "vigilant and distrustful superintendence"- Thomas Jefferson
distrustful