A few Sundays ago, as on most Sundays, I was the guest preacher at one of the churches I work with in the Episcopal Diocese of North Carolina. Before the service, the rector and I stood in the narthex, greeting parishioners as they entered the building.

As people gathered, they greeted each other and their priest warmly -- laughing, hugging and shaking hands. Almost everyone also introduced themselves to me, the stranger in their midst, and welcomed me to their community. By the time the service ended, it felt as though we were all old friends.

Afterward, as I stood at the doorway, most of these folks thanked me, complimented my sermon and asked me to stay and have a cup of coffee. The rector and several parishioners even invited me to lunch, but sadly, I had to decline because of other commitments on my schedule.

Although I regularly have lunch with parishioners, such spontaneous invitations are rare. Indeed, the kind of hospitality I received that Sunday is practically nonexistent. Serving in a different church every Sunday, I see a lot of churches, and I cannot remember another church where I was so warmly welcomed.

Yet whenever I ask congregations to tell me what makes them distinctive, to describe for me their very best qualities, they almost always give me the same answers. They are "friendly" and "warm," they tell me. "We are," they say, "like family."

I'm not seeing it.

Maybe it's me, but most churches I visit aren't particularly friendly. Some aren't friendly at all. When I get there, the doors -- assuming I can find the entrance -- are closed and often locked. Once somebody lets me in, I'll find one or two people busy getting everything ready for the service, but they typically don't say hello or welcome me. Soon, others arrive and take their seats, but they don't often greet each other or me.

Afterward, people may shake my hand as they file out the door. But even this doesn't happen as much as it used to. Instead, members stop in the aisle and visit, sometimes until long after I've headed to the sacristy to change clothes. Later, at the coffee hour, I sometimes, just to test my theory, get a cup of coffee and stand in the center of the room to see whether anyone will speak to me. Usually, I stand alone for a long time.

Congregations and other clergy get defensive whenever I tell them about these experiences. If only I visited their church, they say. There, I would be warmly welcomed. But I'm not convinced. I have seen this in so many churches; odds are, theirs is no different.

But believe it or not, friendliness isn't really my primary concern. Though I wish all our churches were more like the one I visited a few weeks ago, a lack of friendliness is not why our congregations are in decline.

Instead, what I'm observing is a sign of something deeper. It's about much more than handshakes and welcome. Every day, I wonder: Why do some people still go to church while so many others don't? How and why does Christianity in 21st-century America look different than it ever has before?

Based on my experience, the family metaphor may indeed be apt. We are more like families than we realize, in ways that are not always good. Like families, churches can be very close-knit groups, with a select few people who aren't really all that excited about bringing other people in. What group has higher barriers to entry than a family? You can't just wander in. You can only join through birth, adoption or marriage.

No wonder we don't act like we're expecting guests. No wonder, even in a time of decline, we're not putting out the welcome mat. Too many churches are like actual families, slowly bringing in and incorporating new members but rarely going out looking for them.

We don't expect new faces at the door. We are bastions of tradition and stability for a reason. We face our decline by protecting and nurturing what we have. We are not unfriendly, exactly, as much as we are inwardly focused.

And yet Jesus had a different take on family, one that wasn't focused on self-preservation: "Everyone who has left houses or brothers or sisters or father or mother or children or fields, for my name's sake, will receive a hundredfold, and will inherit eternal life" (Matthew 19:29 NRSV).

Maybe our challenge isn't to make our churches "friendlier" but to rethink notions of family that may be preventing us from following Jesus. If church is a "family," then maybe Jesus is calling us to adopt a broader vision of family -- and perhaps occasionally even to leave our family, if only for a while, to go and make disciples of all the world.

A warm smile and a hello, standing on our own safe turf, is better than nothing. But we are called to so much more. What if, as Jesus said, we occasionally left our houses, our places of worship, joining others on Sunday or having services in public places?

What if we sought out strangers where they are, to share the gospel with them? What if we risked being the stranger and opened ourselves on occasion to discovering hospitality where we least expect it?

The gospel is not easy. It is not familiar. And it always pushes us to follow the risen Christ into places we have not gone before. We are called to something deeper than waiting for people to wander into our familiar, homelike church and then remembering to say hello. We are called away from "family," and toward eternal life.