Luke 6:43-45

For there is no good tree that bringeth forth corrupt fruit; nor again a corrupt tree that bringeth forth good fruit. For each tree is known by its own fruit. For of thorns men do not gather figs, nor of a bramble bush gather they grapes. The good man out of the good treasure of his heart bringeth forth that which is good; and the evil man out of the evil treasure bringeth forth that which is evil: for out of the abundance of the heart his mouth speaketh.