(RNS) The cascade of church closings has begun.

There were three Roman Catholic churches shuttered last week in Bridgeport, Conn., and among mainline Protestant churches across the nation, it’s one sad demise at a time. Most recently: the Episcopal cathedral in Wilmington, Del.

It’s always the same scenario: expensive building and declining membership, inadequate financial support, aging congregation and insufficient flow of new members.

I wonder if church leaders will ever see the connection. They allowed a building to define them. They poured resources into bricks and mortar and drove off those who were seeking God, not yesterday’s construction project. They worked hard to raise funds — for a building, not for a mission.

They became like a family that had no purpose unless they were eating dinner at a certain table. They saw themselves as a “worshipping congregation,” not a faith community. They existed to gather in a certain place for liturgy. It mattered intensely to them, but to no one else.

We’re going to hear this sad scenario again and again. An estimated one-half to two-thirds of mainline congregations are no longer viable, as long as they insist on inhabiting inherited facilities. If that happens, the progressive Christian movement in America will be hollowed out, depriving American culture and politics of a vital voice.

And it’s all because yesterday’s wealth paid for lovely buildings and today’s congregants made an idol of those facilities. They failed to see that times had changed, people needed something else, and keeping old doors open was both futile and unimportant.

Church leaders need to read Exodus and the wilderness wandering. When the Hebrews stopped for the night, they made camp. Those camps were never more than temporary. Their destination was Canaan, a land they had never seen, not the particular land they occupied for a night.

So, too, with Jesus, who kept his people moving, not settling. They were sent out to transform lives, not to plant facilities on street corners.

Too many Christians have sought a permanence that was never God’s promise to them, pouring their lives and resources into stopping, not moving. They found pride in stained glass and age-darkened wood, not in transformed lives. They made the rituals of settledness — Eucharist at a certain altar, preaching from a certain pulpit, generations gathered in time-honored venues — more important than the breaking of new ground, touching of new lives, seeking of God’s new call, greeting God’s new day.

Change became the enemy, and a God who has always been about change was frozen out. New generations that were seeking that God went elsewhere. The permanence that some considered their holy duty became, instead, their death knell.

What now? This is a question many institutions are asking. Bricks-and-mortar colleges find themselves stuck with unsustainable campuses. Businesses find their large stores no longer attract customers in an age of online retail. Suburban housing developers carry unsold inventory as people choose urban living. Libraries struggle to house books in an age of online research and Kindle reading.

Each of these transitions is greeted as loss, failure, even betrayal. Few have the heart to close a campus or give away books. I wish faith communities could show the way and say to the perplexed, “Friends, these were temporary shelters. Life is onward. Transformation is our purpose. We have each other and holy purpose, and that — more than any building — is what matters.”

(Tom Ehrich is a writer, church consultant and Episcopal priest based in New York. He is the author of “Just Wondering, Jesus” and founder of the Church Wellness Project. His website is http://www.morningwalkmedia.com. Follow Tom on Twitter @tomehrich.)