The small group of men gathered over soup, salads and flat-bread sandwiches at their regular Tuesday lunch table at Houlihan’s at the Galleria of Mt. Lebanon.

The waiter filled their coffee and soft-drink orders, which he knows by heart. The men bantered a little about the Pirates’ latest acquisition and had some fun at the expense of one of their regular attendees, absent for a winter sojourn down South.

But without losing its casualness, the conversation held to a purpose. “How’s everyone’s week?” one of them asked. “... Hey, what’s going on with you, anything?”

They shared anxieties about aging parents and grown-up children. They told of searches for new jobs and overflowing inboxes at existing jobs. They committed to praying for each others’ struggles.

“It’s the highlight of my week,” David Redding, 59, of Mt. Lebanon said of the group, which he joined the way most people do, at the invitation of a friend.

The men have been meeting only since last summer, but they’re part of a much older movement — the Pittsburgh Experiment, a nondenominational Christian group that is marking the 60th anniversary of its founding Saturday.

Launched by the late Rev. Sam Shoemaker in 1955, it marked an effort to bridge the pieties of Sunday worship with the realities of the workweek.

Shoemaker — a priest at Calvary Episcopal Church in Shadyside — proclaimed his hope that “God would be the same to Pittsburgh as steel is to Pittsburgh.”

Groups met everywhere from the Duquesne Club and the U.S. Steel headquarters to the Aliquippa plant of Jones & Laughlin Steel Corp.

The steel may be largely gone now, but these groups are the direct ancestors of today’s “Experimenters,” meeting at Houlihan’s as well as various Panera Bread, Eat’n Park and other sites in and around Pittsburgh. Some are for men or women only, others are mixed.

Racquel Montgomery of North Braddock, who leads a monthly group in South Park, said the group offers a “place where you can be safe” and share struggles.

“In the age of social media, we think people could connect. It think it’s really not true,” said Ms. Montgomery, 55. “You see all the entries on Facebook shouting for connection. You read people sharing their pain to an outside world and some people would answer, but there’s really no connection. The best connection is still face to face.”

The Pittsburgh Experiment was one of the last major initiatives for Shoemaker, who was such an energetic advocate for one-on-one evangelism that the Rev. Billy Graham once said that no one “in our generation has made a greater impact for God on the Christian world, than did Samuel Shoemaker.”

Shoemaker, who died in 1963, was previously a parish priest in New York and influenced a recovering alcoholic, Bill Wilson, who went on to launch Alcoholics Anonymous. Wilson credited the priest with inspiring many of AA’s founding principles, including reliance on a higher power, mutual support and confidentiality in a small-group setting.

Such principles — while less formalized — also found their way into the Pittsburgh Experiment. The Experiment is also explicitly Christian, while the “higher power” of Twelve Step groups often has taken on various definitions.

Since its founding, the Experiment also has spawned a retreat and conference ministry and an “Employment Anonymous” group for the jobless, and it helped inspire college ministries.

Ground rules for Experiment groups are simple. What’s said there, stays there. Participants don’t have to be Christians, and they have a right to remain silent. It’s about experience, not doctrine.

“We don’t give advice,” added Dan Isadore, 30, of Highland Park. He’s associate director of the Pittsburgh Experiment and a participant in the Mt. Lebanon group. “Part of it is, after you’ve verbalized something enough, you’ve realized what the problem is.”

The aim is not to supplant church but to supplement it.

“A lot of guys wouldn’t go into a church,” said John Rohaly, 73, of Bethel Park, a longtime Pittsburgh Experiment participant and board member. “We want them to feel comfortable.”

Mr. Rohaly was a young business owner in the 1960s, working in the same Downtown building as the Pittsburgh Experiment, when he got to know the gregarious pastors who were directing the program. Skeptical at first, he accepted their invitations to meetings at a Downtown YMCA.

“Slowly I started to see men’s lives change,” he said. “I started to think, maybe there’s something to this.”

At an Experiment-sponsored retreat, he made an enduring Christian commitment.

“I really don’t think that would have happened in a church for me,” he said, because at the time, he was convinced “those people are all hypocrites.”

He was hardly alone with such attitudes even in the mid-20th century, the high-water mark of organized religion, which prompted Father Shoemaker’s innovations.

“I think Sam was absolutely a genius and way ahead of his time,” said the Rev. Ted Kerr, executive director of the Sewickley-based Pittsburgh Experiment. “Think back to the 1950s, when it was largely a Christian culture. That doesn’t mean everybody had a lively faith.”

Rather than starting with preaching, Father Shoemaker invited people to share their experiences, including struggles at work or home.

Then they would do the “experiment” that gave the movement its name. It was right out of the 1950s marketing for shaving cream and toothpaste: Father Shoemaker challenged people to try prayer for 30 days and see if it made a difference.

Often, said Rev. Kerr, the obstacles themselves didn’t change, but the person doing the praying developed a more hopeful attitude — helping mend relations with bosses and spouses.

Rev. Kerr, 44, of Cranberry traces his own conversion to an Experiment group he joined in the 1990s at a time of struggles at work and home.

Some people get converted by an evangelist’s direct appeal, he said. “Other people like Ted Kerr will find God at the lunch table with other misfits like him, talking about problems and then praying about them.”

The Pittsburgh Experiment will mark its 60th anniversary at 6 p.m. Saturday at the Omni William Penn Hotel Grand Ballroom. The main speaker will be Maggie Peale Everett, wife of the late Rev. Paul Everett, a longtime Experiment director, and daughter of the late Rev. Norman Vincent Peale, a renowned minister and supporter of Shoemaker. Information is at pittsburghexperiment.org/​60th.

Peter Smith: petersmith@post-gazette.com, 412-263-1416 or on Twitter @PG_PeterSmith.

First Published: February 22, 2015, 5:00 a.m.