Either declare the tree good and its fruit is good, or declare the tree rotten and its fruit is rotten, for a tree is known by its fruit. You brood of vipers! How can you say good things when you are evil? For from the fullness of the heart the mouth speaks. A good person brings forth good out of a store of goodness, but an evil person brings forth evil out of a store of evil. I tell you, on the day of judgment people will render an account for every careless word they speak. By your words you will be acquitted, and by your words you will be condemned.
(Matthew 12:34-37, NAB)