Matthew 7:15-20

15 `But, take heed of the false prophets, who come unto you in sheep's clothing, and inwardly are ravening wolves.

16 From their fruits ye shall know them; do [men] gather from thorns grapes? or from thistles figs?

17 so every good tree doth yield good fruits, but the bad tree doth yield evil fruits.

18 A good tree is not able to yield evil fruits, nor a bad tree to yield good fruits.

19 Every tree not yielding good fruit is cut down and is cast to fire:

20 therefore from their fruits ye shall know them.