Matthew 7:20

Wherefore by their fruits ye shall know them.

So far as the test of trees is concerned, men's judgment in their case is so definite and absolute that they do not hesitate to cut down and burn a bad tree, knowing very well that it is beyond all possibility for that tree to bring forth good fruit the next year. But this judgment will strike also those that are guilty of false teaching and living, whose fruits must finally reveal the condition of their hearts. Theirs will be the punishment of the fire of hell. In the meantime the Christians must not forget their duty to test and examine the doctrine and the works of the false teachers, lest they become guilty of laxness in spiritual matters. "No false doctrine or heresy has ever originated without having had this sign which He here indicates, that they have produced other works than those commanded and ordained by God... Let him that wants to judge correctly do as Christ here teaches him, and take their works and fruits, holding them beside God's Word and commandments; then he will soon see how well they agree... Thus thou hast a sure judgment which cannot fail, as Christ teaches thee to know them by their fruits. For I also have read up about all heretics and sects, and have found that they always made and brought forth something different from that which God commanded and enjoined, the one in this, the other in that article. The one has prohibited eating all things; a second, marriage; a third has condemned all government, every one choosing his own; and I conclude that they all walk on this path."