This post was first published during May 2014. –ed.

True biblical discernment is grounded in the knowledge and love of the truth—as Paul said in 1 Thessalonians 5:21, every discerning believer must “hold fast to that which is good.” But that’s not the only ingredient. Too many pastors and church leaders today believe that if they just preach the truth, their people will be able to avoid error by osmosis. True discernment doesn’t work that way, as Paul made clear in his very next line to the Thessalonians: “Abstain from every form of evil” (1 Thessalonians 5:22).

The word translated “abstain” is a very strong verb, apechō, meaning “hold oneself back,” “keep away from,” “shun.” It is the same word used in 1 Thessalonians 4:3, “abstain from sexual immorality,” and 1 Peter 2:11, “abstain from fleshly lusts.” It calls for a radical separation from “every form of evil.” This would include evil behavior, of course. But in this context, the primary reference seems to be evil teaching—false doctrine. Having examined everything in light of God’s Word, when you identify something that does not measure up—something that is evil, untrue, erroneous, or contrary to sound doctrine—shun it.

Scripture does not give believers permission to expose themselves to evil. Some people believe the only way to defend against false doctrine is study it, become proficient in it, and master all its nuances—then refute it. I know people who study the cults more than they study sound doctrine. Some Christians immerse themselves in the philosophy, entertainment, and culture of society. They feel such a strategy will strengthen their witness to unbelievers.

But the emphasis of that strategy is all wrong. Our focus should be on knowing the truth. Error is to be shunned.

Granted, we cannot recede into a monastic existence to escape exposure to every evil influence. But neither are we supposed to be experts about evil. The apostle Paul wrote, “I want you to be wise in what is good and innocent in what is evil” (Romans 16:19).

In the King James Version, 1 Thessalonians 5:22 is translated “abstain from all appearance of evil.” The word translated “appearance” is eidos, literally “that which is seen.” The New American Standard Bible gives the better sense with “every form of evil.” We are to reject evil however it appears, to shun every manifestation of it.

This explicitly rules out syncretism. Syncretism is the practice of blending ideas from different religions and philosophies. Some people—even some professing believers—devour materials from every cult and denomination, looking for good in all of it. Whatever they deem good, they absorb into their belief system. They end up designing their own unique religions based on syncretism.

A syncretist might attempt to use 1 Thessalonians 5:21 to justify his methodology: “Examine everything carefully; hold fast to that which is good.” That is, after all, precisely what he is doing—examining everything. But what he is really doing is actually the opposite of what this passage demands. Verse 21 is balanced by verse 22: “Abstain from every form of evil.”

Erroneous doctrine is no place to look for truth. There is usually some point of truth even in the rankest heresy. That is Satan’s subtle strategy. He often sabotages the truth by mixing it with error. Truth mixed with error is usually far more effective and far more destructive than a straightforward contradiction of the truth. If you think everything you read or hear on Christian radio and television is reliable teaching, then you are a prime target for reckless faith. If you think everyone who appears to love the truth really does, then you don’t understand the wiles of Satan. “Satan disguises himself as an angel of light,” Paul wrote. “Therefore it is not surprising if his servants also disguise themselves as servants of righteousness” (2 Corinthians 11:14–15).

Satan also disguises his lies as truth. He doesn’t always wage war openly against the gospel. He is much more likely to attack the church by infiltrating it with subtle error. He uses the Trojan-horse stratagem by placing his false teachers in the church, where they can “secretly introduce destructive heresies” (2 Peter 2:1). He puts his lies in the mouth of someone who claims to speak for Jesus Christ—someone likable and appealing—then he spreads his perverse lies in the church where they can draw away Christ’s disciples (Acts 20:30). He attaches Bible verses to his lies (Matthew 4:6). He uses deception and hypocrisy. He disguises falsehood as truth. He loves syncretism. It makes evil look good.

That’s why we are to examine everything carefully and shun whatever is unsound, corrupt, or erroneous. Doing anything less is deadly. Millions in the church today are being overwhelmed by the Trojan-horse ploy by calling for the integration of secular ideas and biblical truth. Others are easily duped by anything labeled “Christian.” They don’t carefully examine everything. They don’t hold fast to the truth. And they don’t shun evil. As a result, they are left vulnerable to false doctrine and have no defense against reckless faith.

That is not discernment.

(Adapted from Reckless Faith.)