Matthew 7:16-17

7:16 Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? 7:17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit.

James 3:13

3:13 Who [is] a wise man and endued with knowledge among you? let him shew out of a good conversation his works with meekness of wisdom.