As Christianity declines as a force to be reckoned with in American social life, what is left of the Church has been trying to figure out ways to attract non-believers. At least, that’s what I believe is driving the importation of pop music into sacred spaces and sacred events. It strikes me that it is simply no coincidence that polka masses and easy liturgical listening were “innovated” around the same time we all rejected our grandmother’s traditions. To attract the world, we needed to ape the world.

Thus, we are now entering our second, or even third, generation of worship wars. It is hard to deny which side has won. While “liturgical” or “traditional” worship has its holdouts and—like Israel had its remnant—always will, contemporary worship has glided in for a soft landing at the majority of Protestant congregations and many Catholic parishes as well. “Contemporary” worship is now the default and the standard; “traditional” worship has become the exception.

To be fair, there is a lot of grey area in this debate. There are “blended” services, which try to meet somewhere in the middle. There is contemporary music in the midst of an ordered liturgy. There are multiple service options at one congregation. Somewhere between “High Solemn Mass” and Hillsong is where most congregations find themselves, and there is often no fault to be found there.

Still, for those Christians who give a rip, and for those of us who know that how we worship is critical to honoring God, forming disciples, and showing who we are to the world, worship really matters. It is not a question of adiaphora—something non-essential. A worship service that is not, in fact, an actual worship service does no one any good at all. If anything, it does harm. Bad worship practices create confusion, encourage competition, and do not reflect the holiness of God.

So how do you know when someone has actually traversed the boundary of authentic Christian worship? And who is to be the final judge of such a thing? The answer must be made on a case-by-case basis, of course, which is the prudent way to make judgements about just about anything. But I’d like to offer a way to frame the debate that will at least help the conversation move forward.

If you are at all interested in the debate regarding evolution, you are probably familiar with the terms “microevolution” and “maroevolution” already. Darwin’s theory of evolution contends that, given enough time and changing circumstances, whole species will adapt and change into other whole species. (You know it is a new species when it can no longer reproduce with the other species.) That is big-picture, macroevolution, change from one species to another.

Microevolution is change within a species. The finch’s beak grows longer, this bacteria is antibiotic resistant, this person’s skin is lighter, etc. This is not wholesale change from one species to another, but rather, change and adaption within an identifiable and categorical species.

In our case, the species is something we might call “Christian Worship.” And under that species, there is room for a lot of adaptation, change, and matters of opinion, but there is still a sine qua non of Christian worship.

Perhaps only God knows where that proverbial line in the sand is, but there is a line where one crosses from one species to another. The absolute essentials of Christian worship are gone, and therefore, though it takes place in a “church”, is led by a “pastor,” and calls itself “worship,” it just isn’t.

It would be extremely helpful—such wishful thinking, I know!—if Christians could agree on what that sine qua non of Christian worship actually is so we could have some kind of boundary. (Then we could safely excommunicate all Hillsong congregations from fellowship on the basis of false worship.)

I have my list. Christian worship services should include, if not every week, then regularly:

•    Confession and Forgiveness (Psalm 32 and 51)

•    The singing of psalms and hymns (Ephesians 5 and Colossians 3)

•    The reading of scripture (Acts 2:42)

•    Offering praise and worship of God (the entire Psalter)

•    Praying for those in power and for those who are sick (1 Timothy 2 and James 5)

•    Preaching (following the example of Jesus himself and the apostles)

•    Celebrating the Lord’s Supper (Matthew 26)

•    Receiving a benediction (Numbers 6 and the end of most of Paul’s letters.)

•    Sharing the peace of Christ, as Paul did in all of his letters and as Jesus described the saints of God as peacemakers.

I would be willing to argue that worship services that do not regularly include what is on that list have simply evolved right out of what can meaningfully be considered Christian worship. And, again, just because a “pastor” in a “church” calls its one-hour time on Sunday morning together “worship,” this doesn’t mean that it is. There ought to be, in any sane world, limitations around what Christians consider sacred and good.

Now within that list above is room for all kinds of cultural expression, languages, variation, music styles, etc. The Western Rite need not be dogmatized. Different expressions of worship should be encouraged and appreciated, so long as we are appreciating microevolution within a recognizable species.

What we are seeing in much of what calls itself Christian worship is just not Christian worship. It has evolved right out of the conversation. The Western Rite and Hillsong—to continue with the analogy—could not reproduce. They’re too different.

So maybe this language of “species” can be a helpful tool is describing our dislike—or even disgust—of what is pretending to be worship when it is obviously something else. And maybe we can begin to have a real discussion about what actually constitutes authentic Christian worship and why. Every Christian should be able to create a list of their own like I have above. Mine may not be perfect, but at least it is enough to begin a conversation.