It's an experience that most journalists have had, at one time or another. You have just interviewed someone who is really interesting and, perhaps, an important leader in their field. The interview eventually turns into a conversation, usually about the topics linked to the topic being discussed or the details of the person's work.

I had several chances -- over the space of a decade or two -- to talk to the late pollster George Gallup, Jr. It is not surprising that he enjoyed talking about trends in American religion. Me too. He enjoyed talking about interesting questions linked to religious issues. Me too.

This brings us, of course, to the "tmatt trio" -- the three basic doctrinal questions I have long used to probe fault lines among Christian leaders and their followers. The goal is to ask the questions and then listen to the content of the answers, which are almost always highly nuanced and are often revealing.

Gallup and I discussed these questions on several occasions. I have also discussed my "trio" with other pollsters over the years, such as Ed Stetzer of LifeWay Research. Now, his team has released a new survey that includes variations on the "trio." That led to the following Universal syndicate "On Religion" column, which ran last week. The sequel goes to the syndicate tomorrow. 

If the goal was to map the evolving landscape of American religion, the late George Gallup, Jr., once told me, it was crucial to keep asking two kinds of questions.

The first kind attempted to document what never seemed to change or things that were changing very, very slowly. Thus, Gallup urged his team to keep using old questions his father and other researchers in the family business began asking in the 1940s and '50s, such as how often people attended worship services, how often they prayed and whether they believed in God. 

The second kind of question, he said, tested whether these alleged beliefs and practices affected daily life.

"We revere the Bible, but don't read it," he warned, in one 1990 address. "We believe the Ten Commandments to be valid rules for living, although we can't name them. We believe in God, but this God is a totally affirming one, not a demanding one. He does not command our total allegiance. We have other gods before him."

About that time, I shared three questions I had begun asking Christian leaders, based on our discussions in previous interviews. The key, Gallup affirmed, was that these were doctrinal, not political, questions. My journalistic goal was to probe doctrinal changes that revealed fault lines in churches. The questions were:

* Are biblical accounts of the resurrection of Jesus accurate? Did this happen?

* Is salvation found through Jesus, alone? Was Jesus being literal when he said, "I am the Way, the Truth, and the Life. No one comes to the Father except through me."

* Is sex outside of marriage a sin?

Through the years, I have discussed these questions -- GetReligion.org colleagues call them the "tmatt trio" -- with other journalists and additional pollsters, seeking overlapping insights. However, the leaders of LifeWay Research recently went so far as to write these questions into a new "Theological Awareness Benchmark Study" conducted for the Ligonier Ministries of Samford, Fla.

The results, once again, echo decades of work by Gallup and other pollsters indicating that surprisingly high numbers of Americans affirm -- in words -- fairly traditional religious beliefs. However, when questions push them toward actual conflicts with the content of mainstream culture, an increasing number of Americans waffle and move toward what LifeWay President Ed Stetzer calls the "mushy middle."

On one side -- approximately 25 percent or less of those polled -- are "convictional" believers who are actively practice their faith, he said, in a telephone interview. On the other side are the truly secular, vaguely spiritual or simply "religiously unaffiliated" Americans -- the growing "nones" camp that received so much media attention after a 2012 study released by the Pew Forum on Religion and Public Life.

To no one's surprise, the resurrection question drew the most positive responses -- with 45 percent of those polled strongly affirming that doctrine and 23 percent agreeing "somewhat." At the denominational level, 91 percent of evangelical Protestants affirmed the resurrection, to one degree or another, along with 84 percent of black Protestants, 73 percent of "mainline" Protestants and 73 percent of Catholics.

Concerning belief that salvation is through Jesus alone, 35 percent strongly agreed and 18 percent agreed "somewhat." However, there was clear evidence of denominational fault lines -- with 85 percent of evangelicals and 74 percent of African-American Protestants agreeing. However, only 55 percent of "mainliners" and 45 percent of Catholics affirmed this doctrine.

Similar fissures on my question, with 31 percent strongly agreeing, and 17 percent "somewhat," that sex outside of marriage is sin -- but 26 percent strongly disagreeing and 17 disagreeing "somewhat." Answers again varied in different pews, with 76 percent of evangelicals and 74 percent of black Protestants taking the traditional stance, as opposed to 44 percent of mainline Protestants and only 40 percent of Catholics.

In Gallup terms, the resurrection question probed an ancient doctrine that many of those polled would find hard to reject. The questions about salvation and sex pushed many people into conflict with modern American culture.

"America is a churched nation, for the most part. Most Americans are either going to church or they used to go to church," Gallup told me in 2004. "At some point we need to start focusing more attention on what is happening or not happening in those churches. ... Are our people learning the basics? Is their faith making a difference in their lives?"