For the first time since launching his presidential bid, controversial business tycoon Donald Trump has talked about his Christian faith, professing his love for God.

Questioned by Republican pollster Frank Luntz at the Family Leadership Summit in Ames, Iowa, on Saturday, Trump said he is Presbyterian. He also said he likes going to church.

"People are so shocked when they find out I am Protestant. I am Presbyterian. And I go to church and I love God and I love my church," he said at the event, attended by several conservative Christian organisations.

The Republican presidential hopeful also recalled his fondness for his late pastor, Rev. Norman Vincent Peale. Peale, who died in 1993 at the age of 95, used to preach at the Marble Collegiate Church in New York City.

"He was so great. He would give a sermon, and you'd never want to leave," Trump said.

In yet another controversial statement, the businessman admitted that he is not sure that he has ever asked God for forgiveness.

"I am not sure I have. I just go on and try to do a better job from there. I don't think so," Trump said, when asked by Luntz if he ever asked for forgiveness from God.

Trump, who has openly opposed same-sex marriage and abortion, said he just tries to correct his mistakes the best way he can.

"I think if I do something wrong, I think, I just try and make it right. I don't bring God into that picture. I don't," he said.

The Republican presidential aspirant also refused to apologise for his recent statements disparaging to Senator John McCain, whom he said only became a war hero because he was captured.

Trump further said that although he has not asked God for forgiveness, he feels "cleansed" when he participates in Holy Communion.

"When I drink my little wine—which is about the only wine I drink—and have my little cracker, I guess that is a form of asking for forgiveness, and I do that as often as possible because I feel cleansed," he said. "I think in terms of 'let's go on and let's make it right.'"