Another passage that comes to mind about the importance of believers being discriminate in discerning and safeguarding truth, especially as it pertains to the Gospel message (see my related post) is Philippians 3:2-3 where Paul issues the same command 3 times. The text reads:
Watch out for those dogs, those evildoers, those mutilators of the flesh. For it is we who are the circumcision, we who serve God by his Spirit, who boast in Christ Jesus, and who put no confidence in the flesh.
Paul insists that believers in Philippi (and us by extension) must avoid legalists and their legalism.
There is no hint that these people of whom Paul warns are literally present in Philippi. But, the threat of their false teaching was real. There was not a substantial Jewish population in Philippi, but Paul regularly had to defend the purity of the Gospel message against Judaizers—Jewish “Christian” missionaries who came on the heels of Paul teaching adding conditions to the Gospel that were not part of the Gospel.
The warning is powerful and strong, indicated by the repetition of “Watch out.”
Βλέπετε τοὺς κύνας (“Watch out for those dogs”)
βλέπετε τοὺς κακοὺς ἐργάτας (“Watch out for those evildoers”)
βλέπετε τὴν κατατομήν (“Watch out for those mutilators [of the flesh]”)
All three expressions: a) describe the same group of people; b) are beyond being descriptive and sarcastic—they are pejorative, insulting, and full of emotion, and c) are inversions of Jewish boasts, viz., the things that set first-century Jewish people apart are the very things that condemn them. These legalists are called: (1) “dogs”that represent everything unclean and vile vis-à-vis ceremonial purity and those who submit to Jewish dietary restrictions (cf., Mt. 7:6). In Jewish piety, dogs and Gentiles were synonymous (Mk. 7:25-28). In biting irony Paul insists it is the Jews who are to be regarded as Gentiles—the worst of insults; (2) they are “men who do evil” is an expression used for God’s enemies and all those who do not practice God’s Law (Ps. 5:5; 34:16; 139:21-22; Pr. 10:29) vis-à-vis the strict observance of the Law (cf., Lk. 18:20-21). Paul claims that those who pride themselves in keeping the law actually do evil (see Rom. 2:12-15 for a related Pauline view of the Law)! They are also (3) “mutilators of the flesh” which represents circumcision and thus genuine, pure-bred Jews vis-à-vis the pagan religions who often performed circumcision as a rite of passage. Those who insist that circumcision is a sign of new life in Christ depreciate his work on the cross (cf., Gal. 5:12), thus making the rite of circumcision no better than conversion to a pagan religion!
Conditions that were being added to the Gospel message amounted to legalism—the notion that one must do more than believe and repent as a means for salvation or an indication of salvation. In other words, one’s righteousness (standing before God) is based upon specific performance of Jewish customs, e.g., circumcision, Sabbath observance, food law. In essence, legalism adds a “plus factor” to grace, thus nullifying grace altogether. Those who teach/practice such things engage in a form of “false humility,” which is really pride (see Col. 2:16-23). These Judaizers were insisting that circumcision was the sign of entrance into the new covenant, just as it was for the old. Paul explicitly denies that circumcision has any significance whatsoever for the believer (1 Cor. 7:19; Gal. 5:6; 6:15).
The basis for this false teaching was grounded in a misunderstanding of the function of Old Testament Law. In every case, the Law anticipated the fulfillment found only in Jesus (Rom. 10:4; Gal. 3:24). The temple was pointing to the Temple who is Jesus as the supreme sacrifice (Jn. 2:21). The priesthood pointed to the High Priest who is Jesus (Heb. 5, 7). The sacrifice of bulls and goats signaled the final sacrifice made by Jesus’ crucifixion (Heb. 9:11-28). The Passover looked to the Passover Lamb whose sacrifice is comprehensive and complete (1 Cor. 5:7). Moreover, the OT clearly teaches that God was more concerned with a circumcision of the heart (Deut. 10:16; 30:6; Jer. 9:25; Ezek. 44:9), than mere sacrifice (Hos. 6:6; Mt. 9:13). Paul insists that “a man is a Jew if he is one inwardly; and circumcision is circumcision of the heart, by the Spirit, not by the written code” (Rom. 2:29; see also Col. 2:11-12).
Watch out for legalists and their legalism!