15 Be on the watch for false prophets, who come to you in sheep's clothing, but inside they are cruel wolves. 16 By their fruits you will get knowledge of them. Do men get grapes from thorns or figs from thistles? 17 Even so, every good tree gives good fruit; but the bad tree gives evil fruit. 18 It is not possible for a good tree to give bad fruit, and a bad tree will not give good fruit.
Matthew Henry's Commentary on Matthew 7:15-18
Commentary on Matthew 7:15-20
(Read Matthew 7:15-20)
Nothing so much prevents men from entering the strait gate, and becoming true followers of Christ, as the carnal, soothing, flattering doctrines of those who oppose the truth. They may be known by the drift and effects of their doctrines. Some part of their temper and conduct is contrary to the mind of Christ. Those opinions come not from God that lead to sin.