Now I urge you, brethren, keep your eye on those who cause dissensions and hindrances contrary to the teaching which you learned, and turn away from them. For such men are slaves, not of our Lord Christ but of their own appetites; and by their smooth and flattering speech they deceive the hearts of the unsuspecting. For the report of your obedience has reached to all; therefore I am rejoicing over you, but I want you to be wise in what is good and innocent in what is evil. The God of peace will soon crush Satan under your feet. The grace of our Lord Jesus be with you. (Romans 16:17-20)
Identifying and confronting false teachers is extremely unpopular today. But Scripture calls Christians to discern truth from error, providing guidelines for identifying and dealing with those who try to corrupt Christ’s church with false doctrine.
Paul considered it necessary to insert into his greetings of love this caution against harmful teachings and practices that undermine the truth of Christianity and are its greatest threat. Genuine love will be ready to forgive evil, but it will not condone or ignore it. Those such as Paul, who truly love other believers who are dear to them, will warn them about sin and harm, doctrinal falsehood and unrighteous practices.
Commentary from John MacArthur