And if some of the branches be broken off, and thou, being a wild olive tree, wert graffed in among them, and with them partakest of the root and fatness of the olive tree; Boast not against the branches. But if thou boast, thou bearest not the root, but the root thee. - Romans 11:15-18
Mat 7:18 A good tree cannot bring forth evil fruit, neither [can] a corrupt tree bring forth good fruit.
Mat 7:19 Every tree that bringeth not forth good fruit is hewn down, and cast into the fire.
Mat 7:20 Wherefore by their fruits ye shall know them.