The findings also indicated that a significant number of evangelical believers reject the term "evangelical." Only 69 percent of evangelicals by belief identify themselves as evangelicals.

LifeWay noted that some studies define "evangelical" by self-identification, where respondents are required to pick from a list of religious traditions. In other surveys, the respondents are distinguished by the churches they identify with.

In the LifeWay study, the organization used a set of four questions about the Bible, Jesus, salvation and evangelism and those who strongly agree with all four are considered to be evangelicals by belief.

The results have shown that 15 percent of Americans are evangelicals by beliefs, while 24 percent self-identify as evangelicals.

Evangelicals by belief have been found to be more diverse compared to those who self-identify as evangelicals. Fifty-percent of evangelicals by belief are white while 23 percent are African-American. Fourteen percent are Hispanic and five percent claim another ethnicity.

In contrast, 70 percent of self-identified evangelicals are white, while 43 percent are African-American. Twelve percent are Hispanic and four percent say they are of another ethnicity.

Seventy-three percent of evangelicals by belief say they attend church services at least once a week compared to 61 percent of self-identified evangelicals.

The study also found that 65 percent of evangelicals by belief consider themselves Republicans or lean Republican, while 30 percent identify as Democrats or lean Democratic. Four percent are either undecided or identify as independent.

On the other hand, 64 percent of self-identified evangelicals are Republicans or lean Republican, while 33 percent consider themselves as Democrat or lean Democratic. Only three percent are undecided or identify as independent.

Scott McConnell, executive director of LifeWay Research. said that he was surprised by the results, especially when it comes to politics, as he expected more political differences between the two groups.

"The political differences between them turn out to be very small," McConnell said. He suspected that race and party affiliation play a bigger role in people's voting decisions than their faith does.

"Evangelical religious beliefs by themselves do not explain political behavior. Ethnic group is a better predictor of political behavior, but the best predictor of voting patterns is one's political party identification," he added.

The survey of 1,000 American adults was conducted by LifeWay between Nov. 10 and 12, with a margin of error of about three percent.