It is well known that a diet of junk food is not healthy for the body. It promotes obesity and disease. It produces listlessness and passivity.

There is also, I suggest, a kind of junk food for the mind. It, too, produces spiritual sluggishness, ignorance, and anti-intellectualism.

Let me provide an example. A friend of mine, a pastor of many years, decided to leave his pastorate because of ecclesiological pragmatism that stifled spiritual growth. He saw that “success” in the evangelical church merely required four aspects: a concert-feel worship service, simple practical how-to preaching on popular topics using humor with a non-confrontational challenge, a fun-clean-safe children’s ministry, and a similar teen meeting concurrent with the adult service. Another pastoral leader commented: “At one time our church was stronger in teaching and preaching, but the church was almost dead in that period. So, now we prefer to err by just doing, rather than by teaching and not doing.”

Recently however, I listened to another sermon by Tim Keller (Redeemer Presbyterian Church, Manhattan) that clearly is not spiritual fast food. His sermons provide a great example of the kind of preaching that we lack in many evangelical churches. He avoids the pitfall of spiritual pragmatism or the false dichotomy between theology and ethics, thinking and doing.

Keller’s sermons (and I think the key to his broad impact) is that he teaches before he tells us what to do. (And, he makes it interesting. He doesn’t bore us.)

It seems that most preaching today, on the other hand, is junk food for the mind. It stresses application alone—evangelical pragmatism—and ignores the theology or biblical rationale for the application. The result is often just rules, religion, and legalism; not wisdom and discernment.

Consider 1 John 4:19: “We love because he first loved us.” Sermons today, I suspect, simply respond to the demand of the congregation: “Just tell us how to do it. Tell us how to love. Be practical. Don’t bore us with teaching that forces us to think or evaluate ourselves or our culture. Don’t explain to us in depth how or why God first loved us as the rationale for how and why we should love others.”

The bottom line, however, is that the church needs biblical teaching not spiritual fast food. Disciples need to learn. They need discipline. They need minds that are literate and fluent with biblical knowledge. The sad truth, though, is that many Christians are bored. They want less instruction and more biblical rationale, more worldview. They need a balanced diet.

To put it another way, ideas have consequences. Think about the right ideas—biblical ideas— and results inevitably follow.