We’ve been working through 2 Timothy on Sunday evenings. Last week I preached from 2 Timothy 3:6-9. It’s a passage–like many in the pastoral epistles–that deals with false teaching. Paul warns against the folly of false teaching (and against the folly of falling for it).

Which leads to the question: what is false teaching and how do we spot it?

Obviously, there is no foolproof scheme for identifying false teaching. Biblical discernment takes years of prayer, preaching, and practice. But there are certain questions that may be help us sift the good from the bad. Here are 15 discernment diagnostic questions I suggested to my congregation.

1. Does the teaching sound strange? This is not fool proof, of course—predestination may sound strange at first. But sound teaching should make biblical sense for those who have read through the Bible every year, go to church every Sunday, and have gone to Sunday school for decades. As an initial question, the longtime Christian should wonder “Why have I never heard anything like this before?”

2. Does it sound too good to be true? Not in the next life, mind you, but in this life. Promises of never failing material well being or relational ease or emotional tranquility are not to be trusted.

3. Does it involve trinkets or relics or holy water? Christianity entails some mystery, no magic.

4. Does it involve prophetic words? Christians may define prophecy differently. I’m not thinking here of a word fitly spoken, or powerful preaching, or wise counsel. I’m talking about “the Lord told me” sort of communication that tell other people what to do and cannot be tested or sifted according to Scripture.

5. Do angels or aliens or seed money play a major role in the teaching? Enough said.

6. Does it feature prominently the word “code”? Bible Code, DaVinci Code, Omega Code. Just stay away.

7. Does the teaching involve secrets? This was the appeal of Gnosticism. It purported to lead the initiate into the realm of secret knowledge. This is what makes me nervous about Masons, Mormons, and even many fraternities and sororities. Unless national security is involved, be wary of groups that are held together by tightly held secrets. Books with “secret” in the title are usually suspect too (Lesslie Newbigin’s The Open Secret being the exception that proves the rule).

8. Does it rely on a cartoon view of God? False teaching tends to cast God as either as a autocratic strongman or a friendly face passing out beads at Woodstock? By contrast, the God of the Bible shines forth with (to use Jonathan Edwards’ phrase) a host of diverse excellencies.

9. Does the teaching use big themes to negate specific verses? We should always interpret Scripture with Scripture, but we must not allow amorphous themes like love or justice or grace to flatten the contours of Scripture.

10. Does it promote an unmediated approach to spirituality? Mysticism, in its technical sense, can be defined as an approach to God apart from mediation. False spirituality tries to foster intimacy with God that does not go through the mediated revelation of Scripture and does not lead one to the mediation of Christ on the cross.

11. Does the false teaching traffic in under-defined terms and slogans? Liberalism starts with an inattention to words. It is the triumph of orthodoxy to be careful with language.

12. Does the teaching neglect the need for repentance? Beware the feel good invitation for everyone to come to the wide open arms. The coming of the Kingdom is not good news for sinners. It is good news for sinners who repent.

13. Does the false teaching or teacher seem obsessed about one person, one doctrine, or one idea? An unsolicited exposé running into the hundreds of pages likely reveals more about the author than the subject.

14. Does it result in an unbalanced presentation of the truth? True Christianity walks the tight rope between complementary biblical truths—truth and grace, Christ as God and man, salvation by faith alone and the necessity of the obedience of the Christian. It was usually the heretics who were guilty of resolving biblical tensions in ways that were too neat and tidy.

15. Does the teaching fit with the Bible’s story line of sin and salvation? How can a holy God dwell in the midst of an unholy people? If the teaching doesn’t make sense as a plot line in that story, I’m suspicious.

Mature Christians do not cast a critical eye on everyone and everything a hair’s breadth different from them. But they are discerning, and they are careful. Guard your heart. Guard your home. Guard the good deposit.