Jesus said to his disciples:
“A good tree does not bear rotten fruit, nor does a rotten tree bear good fruit. For every tree is known by its own fruit. For people do not pick figs from thornbushes, nor do they gather grapes from brambles.

A good person out of the store of goodness in his heart produces good, but an evil person out of a store of evil produces evil; for from the fullness of the heart the mouth speaks.”