If the goal is 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 kind attempted to document things that never seemed to change or that were changing very, very slowly. Thus, Gallup urged his team to keep using old questions his father and others 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 a set of three questions with Gallup that I had begun asking, after our previous discussions. The key, he 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: