Presidential hopeful Senator Barack Obama revived talks on his personal Christian faith this week in an effort to dispel rumours that he is a Muslim.

The Democratic candidate spoke to the popular religious website beliefnet.com and highly respected Christianity Today magazine to set the record straight that he is a "devoted" Christian and never was a Muslim - an allegation that spread through widely circulated accusatory e-mails.

"I have been a member of the same church for almost 20 years, and I have never practiced Islam," Obama stated in a Christianity Today interview posted Wednesday. "I am respectful of the religion, but it's not my own."

Obama's past ties with Islam - including having a Muslim father and stepfather living in the largely Muslim country of Indonesia during his childhood, and having the middle name Hussein - fueled the conspiracy theory that Obama is a Muslim in disguise trying to take over the White House.

"One of the things that's very important in this day and age is that we don't use religion as a political tool and certainly that we don't lie about religion as a way to score political points," the Illinois senator emphasised.

"I just thought it was important to get that in there to dispel rumours that have been over the Internet," he added. "We've done so repeatedly, but obviously it's a political tactic of somebody to try to provide this misinformation."

The Democrat from Illinois recounted that he came to accept Christ in the 1980s when he was working as a young community organiser in Chicago's South Side black neighbourhoods. It was at Trinity United Church of Christ where he felt "drawn to the message of Jesus Christ" and "the power of the church to fortify people in their spiritual journeys". He "submitted" himself to God and was baptised by Trinity United Church of Christ, according to the beliefnet.com interview.

"It wasn't an epiphany. I didn't 'fall out', as they say in the black church," Obama noted. "It was an emotional and spiritual progression, as well as an intellectual one. And it didn't happen overnight."

He said he prays every day on the campaign trail, and before running for president, to be an "instrument of God's will". The oft described charismatic candidate said he applies the Golden Rule to campaign politics, being challenged by his faith to be respectful and courteous to everyone, including his political opponents.

"I do think that being a Christian doesn't mean that you're passive or that you aren't going to confront injustice," Obama said. "What I think is important, though, and is important not just for me, but also for my team....is to at least be scrupulous and honest in how we present our disagreements with other people.

"I try to measure whether what I'm saying is fair by seeing how I would feel if I was at the receiving end of it," said the candidate whose recent verbal volleying with rival Senator Hillary Clinton and former president Bill Clinton has been highly publicised.

Obama, who won the Iowa caucuses, will next battle Democratic rivals in South Carolina Saturday - a state where he has spoken in many black churches and organised a gospel concert to attract black voters.