Proverbs 14:15 in the King James Version
The simple believeth every word: but the prudent man looketh well to his going.
Context
14 The unfaithful will be repaid for his own ways; likewise a good man will be rewarded for his ways.
15 A simple man believes everything, but the prudent man carefully considers his ways.
16 A wise man fears and shuns evil, but the fool is hot headed and reckless.