The majority of American Christians do not believe that Satan is a real being or that the Holy Spirit is a living entity, the latest Barna survey has found.

Nearly six out of ten Christians surveyed either strongly agreed or somewhat agreed with the statement that Satan "is not a living being but is a symbol of evil", the survey found. Forty per cent strongly agreed with the statement while 19 per cent of American Christians somewhat agreed.

In contrast, about 35 per cent of American Christians believe Satan is real. Twenty-six percent strongly disagreed with the statement that Satan is merely symbolic and nine per cent somewhat disagreed.

The remaining eight per cent of American Christians said they were unsure what to believe about the existence of Satan.

Interestingly, the majority of Christians believe a person can be under the influence of spiritual forces, such as demons or evil spirits, even though many of these same people believe Satan is merely a symbol of evil. Two out of three Christians agreed that such forces are real (39 per cent agreed strongly, 25 per cent agreed somewhat).

Likewise, most Christians in the United States do not believe that the Holy Spirit is a living force. Fifty-eight percent strongly or somewhat agreed with the statement that the Holy Spirit is "a symbol of God's power or presence but is not a living entity."

Only one-third of Christians disagreed with the statement that the Holy Spirit is not just symbolic (9 percent disagreed somewhat, 25 percent disagreed strongly). Nine per cent admitted they were unsure.

Interestingly, about half (49 per cent) of those who agreed that the Holy Spirit is only a symbol but not a living entity, agreed that the Bible is totally accurate in all of the principles it teaches. The Bible states that the Holy Spirit is God's power or presence, not just symbolic.

"Most Americans, even those who say they are Christian, have doubts about the intrusion of the supernatural into the natural world," commented George Barna, founder of The Barna Group and author of books analyzing research concerning America's faith.

"Hollywood has made evil accessible and tame, making Satan and demons less worrisome than the Bible suggests they really are," he said. "It's hard for achievement-driven, self-reliant, independent people to believe that their lives can be impacted by unseen forces."

But a large majority of American Christians agree that a person must choose to side with either good or evil. More than six out of ten American Christians strongly agreed (61 percent) with the idea that a person must either side with God or with the devil - that there is no in-between position. Another 15 percent somewhat agreed.

Just one out of ten adults disagreed somewhat (10 percent) and a similar proportion (11 percent) strongly disagreed. Only a few adults (3 percent) did not have an opinion on the issue.

Barna explained that because of the "sheer force of repetition" many Americans "intellectually" accept the idea that you either side with God or Satan and there's no in-between, even though this idea does "not get translated into practice."

Other survey findings include a significant number of self-described Christians believing that Jesus sinned when he lived on earth, contrary to the core teaching of Christianity that teaches the divinity and perfection of Jesus.

More than one-fifth (22 percent) strongly agreed that Jesus Christ sinned when He lived on earth, with an additional 17 percent agreeing somewhat.

However, nearly half of American Christians (46 percent) strongly disagreed with the idea that Jesus sinned, and 9 percent disagreed somewhat. Six percent did not have an opinion on the statement.

The Barna report is based on telephone interviews for two surveys among people who described themselves as Christians. A total of 1,871 adults were randomly selected from across the 48 continental states, with the first 873 interviews conducted in January and February 2008, and the remaining 998 interviews conducted in November 2008.