Luke 6:43-45

For there is no good tree which produces bad fruit, nor, on the other hand, a bad tree which produces good fruit. [Matt 7:16, 18] For each tree is known and identified by its own fruit. For figs are not picked from thorn bushes, nor is a cluster of grapes picked from a briar bush. The [intrinsically] good man produces what is good and honorable and moral out of the good treasure [stored] in his heart; and the [intrinsically] evil man produces what is wicked and depraved out of the evil [in his heart]; for his mouth speaks from the overflow of his heart.