There are three Greek words translated "beware," all of which stress watchfulness and potential danger. In a world under the control of Satan, there are many of his devices which can deceive and undermine the faith and life of the unwary Christian.
Our text cautions against false prophets who appear to be true prophets (or teachers, or pastors), but whose apparent spiritual teachings are subversive of biblical truth. John warns that "many false prophets are gone out into the world" (1 John 4:1), and Jesus said they "shall deceive many" (Matthew 24:11). Jesus also warned that His followers should "beware of . . . the doctrine of the Pharisees and of the Sadducees" (Matthew 16:12). These sects have their respective modern counterparts in the hypocrisy of legalists and the skepticism of liberals, both of which are destructive of true biblical faith and life.
Very relevant to today's humanistic intellectualism is the warning of Colossians 2:8: "Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ." This is the Bible's only reference to philosophy, here evidently equated with "vain deceit."
Finally, the apostle Peter says, "Beware lest ye also, being led away with the error of the wicked, fall from your own stedfastness" (2 Peter 3:17). In context, Peter is referring to those Christian brethren who have distorted the Scriptures in order to seek an accommodation with the naturalistic worldview of establishment intellectuals (2 Peter 3:3-6, 16). Thus, Peter, John, and Christ Himself would urge constant wariness on our part. HMM