15 Keep yourselves also from the false prophets, who come to you in sheep’s clothing, but inwardly they are ravening wolves. 16 Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? 17 Even so every good tree brings forth good fruit, but a corrupt tree brings forth evil fruit. 18 A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit. 19 Every tree that does not bring forth good fruit is hewn down and cast into the fire. 20 So that by their fruits ye shall know them.