How Ben Carson's Seventh Day Adventist faith has helped his campaign

Donald Trump is perplexed that his 2016 Republican opponent Ben Carson has surpassed him in Iowa polls. As Trump in recent days questioned why the former pediatric neurosurgeon is gaining ground, he's also called into question Carson's religious beliefs.

"I'm Presbyterian," Trump said to a crowd in Jacksonville, Florida on Saturday. "Boy, that's down the middle of the road folks, in all fairness. I mean, Seventh-day Adventist, I don't know about. I just don't know about."

On CBS' "Face the Nation" on Sunday Trump insisted that he wasn't trying to insult Carson or the Seventh Day Adventist church -- he simply is "not that familiar with it."

Given that only an estimated 1.2 million Americans belong to the Seventh Day Adventist church, it's likely that plenty of voters are just as unfamiliar with the church as Trump. So far, however, that hasn't blunted Carson's momentum in Iowa, where evangelical voters made up 57 percent of Republican caucus-goers in 2012. In fact, after gaining national notoriety at the 2013 National Prayer Breakfast, the famous physician has successfully cast himself as a staunch conservative whose actions and views are significantly influenced by his faith.

When asked in September to name the biggest difference between himself and Trump, Carson actually took a shot at Trump's religious conviction: "Probably the biggest [difference] -- I've realized where my success has come from, and I don't in anyway deny my faith in God," he said to reporters in Anaheim, California.

On NBC's "Meet the Press" on Sunday, Carson quoted a Bible verse to explain his approach to taking political advice: "Solomon, the wisest man who ever lived, said in Proverbs 11:14, 'In a multitude of counselors is safety.' If the wisest man who ever lived thought that, I certainly believe that," he said.

So far, that approach to leadership seems to be resonating with conservative voters looked for a principled, outsider candidate. A Des Moines Register Poll released on Friday showed Carson leading Trump by nine points among likely Republican caucus-goers in Iowa (28 percent to 19 percent). He won the support of a third of evangelical Christians in that poll.

A day earlier, a Quinnipiac poll out of Iowa showed Carson ahead of Trump in Iowa, 28 percent to 20 percent, among likely GOP caucus-goers. Among white evangelicals, his lead widened 36 percent to 17 percent.

As many as 28 percent of likely caucus-goers in that poll said that they were most interested in finding a GOP nominee who shares their values -- and as many as 84 percent said that Carson does share their values. The next closest candidate was Sen. Marco Rubio -- 68 percent of likely caucus-goers said he shares their values.

Drake University Professor Dennis Goldford, author of The Constitution of Religious Freedom: God, Politics, and the First Amendment, stressed that "values" don't have to necessarily align with religious beliefs.

"For Carson, you can talk about particular religious beliefs and values, and then you can talk about policy prescriptions you believe are derived from those values," he said to CBS News. "At the level of policy positions and beliefs, a lot of evangelicals believe, at least in [recent polls], that their policy prescriptions track Carson's very well."

When it comes to issues like abortion or same-sex marriage, Carson lines up with evangelicals.

Yet, Goldford added, "Do they hold his religious beliefs, per se? That's a trickier question." And it's one that can't be discounted completely, since there is "a small but powerful segment of the Republican Party who sees politics as religion," Goldford said. "Carson's going to sink or swim based upon support from those who see them as two sides of the same coin."

While Mitt Romney, a Mormon, won the Republican nomination in 2012, he lost the Iowa caucuses to Rick Santorum, a Catholic whose campaign put much more emphasis on faith-based values. Overall, Romney did 13 percentage points worse in the primaries among evangelical voters than he did with non-evangelicals, according to a Washington Post analysis. And according to a Gallup survey released in June of this year, 18 percent of Americans say they would not vote for a well-qualified Mormon presidential candidate.

Harvard Divinity School Professor David Holland told CBS News that there is "considerable wariness" toward Seventh Day Adventism but not to the degree that a Mormon candidate would face.

"Theologically, Seventh Day Adventism tends to be a bit closer to mainstream Christianity," Holland said.

Seventh Day Adventism is a branch of Christianity that developed in the second half of the 19th Century as an offshoot of the "Millerites," a group of Christians expecting the return of Jesus Christ to Earth in 1844. When Jesus did not return, a Millerite follower named Ellen White claimed to have prophetic visions that helped explain "The Great Disappointment" and served as the basis of Seventh Day Adventism. One of the church's distinguishing features is that it holds Saturday as the Sabbath, rather than Sunday as other branches of Christianity.

"I think for a lot of us, we're not real familiar with the tenets of that faith, but it's a faith that is Biblically driven, and there's nothing odd about it," Steve Scheffler, an Iowa Republican National Committeeman and president of the Iowa Faith & Freedom Coalition (IFFC), told CBS News.

Certainly, when Iowa voters say they like Carson's values, they're considering his faith, Scheffler said -- how could they not? "If a person has a deep religious faith, it tends to mold their political thinking," he said.

Scheffler stressed, however, that voters also like Carson's willingness to take a principled stand for his beliefs. He cited Carson's remarks that he doesn't view the religion of Islam as compatible with American democracy.

"He's not willing to buckle to the political elites within both parties and the press when he thinks he's right," Scheffler said.

Indeed, last week's Des Moines Register poll asked likely GOP caucus-goers whether or not they thought Carson's statement about a potential Muslim president was an "attractive" comment -- 43 percent called it "very attractive," while 30 percent said it was "mostly attractive."

In fact, Carson's statements about Islam could be interpreted as out of step with the philosophy of the Seventh Day Adventist Church, which has historically stressed the importance of the separation of church and state.

In the religion's early days, there were many states that had laws prohibiting work on Sunday. Many Seventh Day Adventists were jailed and faced a degree of persecution because they didn't recognize the Sunday Sabbath, Holland explained.

"From very early on, they were very sensitive to the power of the state," he said. "Ellen White was quite outspoken on this topic and declared that the union of religious and political power would be one of the signs the world was coming to an end."

When Carson announced his 2016 candidacy in May, the Seventh Day Adventist church released an official statement stressing that the church "has a longstanding position of not supporting or opposing any candidate for elected office... based both on our historical position of separation of church and state."

The statement also noted, "The church has worked diligently to protect the religious rights of all people of faith, no matter what their denominational affiliation."

Now that Carson is gaining ground in the polls, voters may have more questions about his faith -- particularly as opponents like Trump call them into question. Goldford noted, however, that Carson brought the scrutiny upon himself by stressing his religious values on the campaign trail.

"If you want to play the religion [card], you have to accept the fact there will be times you're on defense, as well as offense," he said. "If you're going to stick your foot in the water, you're going to get wet."