Is there any gesture more deflatingly ambiguous than the thumbs-up? It seems positive, but the more you think about it, the more you wonder. And as a professional Awkward Stock Photo Analyst Guy (official title), I know ambiguity.

Take, for example, this photo. There are plenty of ambiguous things about it: Who is this woman, and where did she find a church with such ample parking? How did she flatten her hair so tightly against her head, and which tortured soul is her stylist? Where did she find a polo shirt so tight that we can see the entire topography of her jeans beneath it? Is she a giant, or the Bible she’s holding just really, really tiny?

Fascinating as they may be, though, such questions can’t compare to this photo’s greatest mystery: that peppy, perfectly-45-degree-angled thumbs-up.

As with the perennially enigmatic smile of the Mona Lisa, I imagine scholars will debate the meaning of this parishioner’s paradoxically Ebertian hand gesture for generations to come. Who was this woman, they’ll ask, and why did she feel the need to convey such enthusiasm with the opposable digit on her right hand? Tourists will line up, hundreds deep at a Paris gallery in hopes of solving the mystery before giving up and going to gorge themselves on overpriced wine and cheese. Papers will be written. Debates will be had. Wars, long and bloody, will undoubtedly be fought—all to settle the question of what imbued this woman with such unabashed enthusiasm.

We may never know. But what really matters here is that the church service that clearly just transpired has earned itself an enthusiastic “thumbs-up” from the peanut gallery. Nothing says “You’ve done a somewhat okay job” better than that gesture of sheer adequacy, supported with a forced grin and a beneficent look in your dead, dead eyes. If you stare long enough, you can almost hear her mumbling, “Thank you pastor, I enjoyed the service,” as she rushes out the door, hoping to reach IHOP before the Sunday lunch rush.

It’s a conundrum for pastors, really: is it actually a good thing when people tell you they enjoyed the service? Or worse, your sermon? It means they’ll be back, sure—but will they be back for the right reasons?

No pastor—no pastor with interests beyond cashing a paycheck, anyway—wants people to leave a church service having merely “enjoyed” themselves. Any good pastor wants people to leave having been made to feel the guilt of their sin, reminded of the grace offered in the Gospel, and inspired to do good and shun evil. You don’t want them to leave happy; you want them to leave changed.

This is only occasionally how things work, though.

Most people who change do so slowly. There are exceptions, of course—some hear the Gospel for the first time, fall to their knees, and change their ways overnight. But outside of Dickens, such events are rare. Most of us kick against the goads for years at a time. To the casual observer, we frequently appear to be coasting through life.

But such appearances shouldn’t always be taken as evidence that growth is not occurring. God chooses to mold and shape most of us in normal, mundane ways, like the weather wearing away at a rock—or, perhaps more accurately, like a mother reminding her kid for the millionth time to stop leaving his dirty underwear in the fine china cabinet. We screw up continually, but eventually, the changing seasons begin to herald improvement—and, eventually, our patient Father teaches us to crawl.

So take heart, pastors, preachers, and devoted sermon-sitters—as frustrating as the dismissive, enigmatic “I enjoyed the service” may be, the Spirit is at work. Eventually, the thumbs-up may unfold into an open palm, stretched out toward the needy and upward toward heaven.