Matthew 7:15-20

15 "Beware of false prophets, who come to you in sheep's clothing, but inwardly are ravening wolves. 16 By their fruits you will know them. Do you gather grapes from thorns, or figs from thistles? 17 Even so, every good tree produces good fruit; but the corrupt tree produces evil fruit. 18 A good tree can't produce evil fruit, neither can a corrupt tree produce good fruit. 19 Every tree that doesn't grow good fruit is cut down, and thrown into the fire. 20 Therefore, by their fruits you will know them.