Credulous
Part of speech: adjective
Definition: Excessively ready to believe things; gullible.
Example sentence: O! Desolated Scotland, too credulous of fair speeches, and not aware of the calamities which are coming upon you! If you were to judge as I do, you would not easily put your neck under a foreign yoke.
Unquestioning
Part of speech: adjective
Definition: Believing without question; having absolute loyalty; faithful; doubtless.Naive.