Washington(CNN) Donald Trump pulled no punches as he slammed Ben Carson Thursday morning for questioning his faith. But Carson won't fight back.
Instead, the retired neurosurgeon apologized for firing what the billionaire front-runner perceived as the first shot when Carson on Wednesday called the depth of the two contenders' faith "probably the biggest" difference between them.
"I would like to say to him that the intention was not to talk to him, but about what motivates me," Carson told The Washington Post. "If he took that as a personal attack on him, I apologize, it was certainly not the intent."
Trump hours earlier called in to CNN's "New Day" and laid into his rival, calling Carson -- the first surgeon to separate conjoined twins joined at the head -- just an "OK doctor" and said "you look at his faith and I think you're not going to find so much."
Trump also called Carson's views on abortion "horrendous." Carson is staunchly opposed to abortion now, but was an abortion rights supporter when he was younger and performed medical research on aborted fetuses in 1992.
Who's running for president?
Ted Cruz, Donald Trump, John Kasich, Hillary Clinton and Bernie Sanders,
Businessman Donald Trump
announced June 16 at his Trump Tower in New York City that he is seeking the Republican presidential nomination. This ends more than two decades of flirting with the idea of running for the White House.
"So, ladies and gentlemen, I am officially running for president of the United States, and we are going to make our country great again," Trump told the crowd at his announcement.
Sen. Ted Cruz of Texas has made a name for himself in the Senate, solidifying his brand as a conservative firebrand willing to take on the GOP's establishment. He
announced he was seeking the Republican presidential nomination in a speech on March 23.
"These are all of our stories," Cruz told the audience at Liberty University in Virginia. "These are who we are as Americans. And yet for so many Americans, the promise of America seems more and more distant."
Ohio Gov. John Kasich joined the Republican field July 21 as he formally announced his White House bid.
"I am here to ask you for your prayers, for your support ... because I have decided to run for president of the United States," Kasich told his kickoff rally at the Ohio State University.
Hillary Clinton
launched her presidential bid on April 12 through a video message on social media. The former first lady, senator and secretary of state is considered the front-runner among possible Democratic candidates.
"Everyday Americans need a champion, and I want to be that champion -- so you can do more than just get by -- you can get ahead. And stay ahead," she said in her announcement video. "Because when families are strong, America is strong. So I'm hitting the road to earn your vote, because it's your time. And I hope you'll join me on this journey."
Sen. Bernie Sanders, an independent from Vermont who caucuses with Democrats, announced his run in an email to supporters on April 30. He has said the United States needs a "political revolution" of working-class Americans to take back control of the government from billionaires.
"This great nation and its government belong to all of the people and not to a handful of billionaires, their super PACs and their lobbyists," Sanders said at a rally in Vermont on May 26.
"If you look at his past, which I've done, he wasn't a big man of faith. All of a sudden he's becoming this man of faith. And he was heavy into the world of abortion," Trump said.
Trump is now opposed to abortion, but only after years supporting women's right to abortions, describing himself in 1999 as "very pro-choice."
Carson has been a prominent figure in the evangelical community for years and repeatedly touts on the stump the role faith has played in his life. He jumped onto the conservative political scene when in 2013 he delivered the keynote address at the National Prayer Breakfast, diving into a heavy-handed criticism of President Barack Obama's health care reform measure with Obama at his side.
Despite the harsh criticism, Carson resisted the urge to wage war with Trump.
"The media frequently wants to goad people into wars, into gladiator fights, you know. ... And I'm certainly not going to get into that," he told The Washington Post.
A Carson surrogate -- his business manager, Armstrong Williams -- did go after Trump, suggesting the billionaire was just waiting for an excuse to slam Carson.
"Mr. Trump sounded almost like a schoolyard bully that if you say something I don't like I'm going to come at you with everything I've got on the table," Williams said on CNN's "This Hour."
Donald Trump's rise
President-elect Donald Trump has been in the spotlight for years. From developing real estate and producing and starring in TV shows, he became a celebrity long before winning the White House.
Trump at age 4. He was born in 1946 to Fred and Mary Trump in New York City. His father was a real estate developer.
Trump, left, in a family photo. He was the second-youngest of five children.
Trump, center, stands at attention during his senior year at the New York Military Academy in 1964.
Trump, center, wears a baseball uniform at the New York Military Academy in 1964. After he graduated from the boarding school, he went to college. He started at Fordham University before transferring and later graduating from the Wharton School, the University of Pennsylvania's business school.
Trump stands with Alfred Eisenpreis, New York's economic development administrator, in 1976 while they look at a sketch of a new 1,400-room renovation project of the Commodore Hotel. After graduating college in 1968, Trump worked with his father on developments in Queens and Brooklyn before purchasing or building multiple properties in New York and Atlantic City, New Jersey. Those properties included Trump Tower in New York and Trump Plaza and multiple casinos in Atlantic City.
Trump attends an event to mark the start of construction of the New York Convention Center in 1979.
Trump wears a hard hat at the Trump Tower construction site in New York in 1980.
Trump was married to Ivana Zelnicek Trump from 1977 to 1990, when they divorced. They had three children together: Donald Jr., Ivanka and Eric.
The Trump family, circa 1986.
Trump uses his personal helicopter to get around New York in 1987.
Trump stands in the atrium of the Trump Tower.
Trump attends the opening of his new Atlantic City casino, the Taj Mahal, in 1989.
Trump signs his second book, "Trump: Surviving at the Top," in 1990. Trump
has published at least 16 other books, including "The Art of the Deal" and "The America We Deserve."
Trump and singer Michael Jackson pose for a photo before traveling to visit Ryan White, a young child with AIDS, in 1990.
Trump dips his second wife, Marla Maples, after the couple married in a private ceremony in New York in December 1993. The couple divorced in 1999 and had one daughter together, Tiffany.
Trump putts a golf ball in his New York office in 1998.
An advertisement for the television show "The Apprentice" hangs at Trump Tower in 2004. The show launched in January of that year. In January 2008, the show returned as "Celebrity Apprentice."
A 12-inch talking Trump doll is on display at a toy store in New York in September 2004.
Trump attends a news conference in 2005 that announced the establishment of Trump University. From 2005 until it closed in 2010, Trump University had about 10,000 people sign up for a program that promised success in real estate.
Three separate lawsuits -- two class-action suits filed in California and one filed by New York's attorney general -- argued that the program was mired in fraud and deception. Trump's camp rejected the suits' claims as "baseless." And Trump has charged that the New York case against him is politically motivated.
Trump attends the U.S. Open tennis tournament with his third wife, Melania Knauss-Trump, and their son, Barron, in 2006. Trump and Knauss married in 2005.
Trump wrestles with "Stone Cold" Steve Austin at WrestleMania in 2007. Trump has close ties with the WWE and its CEO, Vince McMahon.
For "The Apprentice," Trump was honored with a star on the Hollywood Walk of Fame in January 2007.
Trump appears on the set of "The Celebrity Apprentice" with two of his children -- Donald Jr. and Ivanka -- in 2009.
Trump poses with Miss Universe contestants in 2011. Trump had been executive producer of the Miss Universe, Miss USA and Miss Teen USA pageants since 1996.
In 2012, Trump announces his endorsement of Republican presidential candidate Mitt Romney.
Trump speaks in Sarasota, Florida, after accepting the Statesman of the Year Award at the Sarasota GOP dinner in August 2012. It was shortly before the Republican National Convention in nearby Tampa.
Trump appears on stage with singer Nick Jonas and television personality Giuliana Rancic during the 2013 Miss USA pageant.
Trump -- flanked by U.S. Sens. Marco Rubio, left, and Ted Cruz -- speaks during a CNN debate in Miami on March 10. Trump dominated the GOP primaries and emerged as the presumptive nominee in May.
The Trump family poses for a photo in New York in April.
Trump speaks during a campaign event in Evansville, Indiana, on April 28. After Trump won the Indiana primary, his last two competitors dropped out of the GOP race.
Trump delivers a speech at the Republican National Convention in July, accepting the party's nomination for President. "I have had a truly great life in business," he said. "But now, my sole and exclusive mission is to go to work for our country -- to go to work for you. It's time to deliver a victory for the American people."
Trump apologizes in a video, posted to his Twitter account in October, for vulgar and sexually aggressive remarks he made a decade ago regarding women. "I said it, I was wrong and I apologize,"
Trump said, referring to lewd comments he made during a previously unaired taping of "Access Hollywood." Multiple Republican leaders rescinded their endorsements of Trump after the footage was released.
Trump walks on stage with his family after he was declared the election winner on November 9. "Ours was not a campaign, but rather, an incredible and great movement," he told his supporters in New York.
Trump is joined by his family as he is sworn in as President on January 20.
Squabbling between Carson and Trump was expected to be the next subplot in Trump's continued domination of the GOP field as Carson has surged in recent polls, rising above the rest of the pack along with Trump in Iowa and national polls. Carson jumped 10 points to second place at 19% in the most recent CNN/ORC poll while Trump continued to rise, snagging 32% of support.
Trump and Carson have so far played nice, but Trump recently suggested he might have to start lashing out if Carson continued to surge behind him.
Carson's criticism of Trump's faith offered Trump the perfect opportunity, allowing him to hit Carson while remaining a "counterpuncher."
"I've realized where my success has come from, and I don't in anyway deny my faith in God," Carson said Wednesday when asked about the difference between him and Trump, before quoting what he said was one of his favorite Bible verses.
"'By humility and the fear of the Lord are riches and honor and life,' and that's a very big part of who I am. I don't get that impression with him," Carson said of Trump. "Maybe I'm wrong, but I don't get that."
Carson told The Washington Post that his comments were interpreted as an attack on Trump.
Trump has pulled strong support from evangelicals, but has also stumbled on questions about his faith, saying that he does not ask God for forgiveness -- a key tenet of Christianity -- and declining to cite his favorite Bible verse in a recent interview. And the New York church that Trump said he attends told CNN that Trump is not an "active member."
Trump, who has repeatedly called himself a counterpuncher, said he was only hitting Carson because he attacked him the day before.
"Who is he to question my faith? When I am -- I mean he doesn't even know me," Trump said. "When he questions my faith -- and I'm a believer, big league, in God and the Bible -- and he questions my faith and he doesn't know me."
Ben Carson's career in politics
Ben Carson attends the National Action Network (NAN) national convention at the Sheraton New York Times Square Hotel on April 8, 2015, in New York City.
Carson speaks during the 41st annual Conservative Political Action Conference (CPAC) at the Gaylord International Hotel and Conference Center on March 8, 2014, in National Harbor, Maryland.
Carson speaks to guests at the Iowa Freedom Summit on January 24, 2015, in Des Moines, Iowa.
Carson is surrounded by supporters as he waits to be interviewed at the annual Conservative Political Action Conference (CPAC) at National Harbor, Maryland, outside Washington on February 26, 2015.
Carson speaks at the South Carolina Tea Party Coalition convention on January 18, 2015, in Myrtle Beach, South Carolina. A variety of conservative presidential hopefuls spoke at the gathering on the second day of a three-day event.
Carson delivers the keynote address at the Wake Up America gala event on September 5, 2014, in Scottsdale, Arizona.
Carson speaks during the 41st annual Conservative Political Action Conference (CPAC) at the Gaylord International Hotel and Conference Center on March 8, 2014, in National Harbor, Maryland.
Carson speaks during the National Prayer Breakfast at the Washington Hilton on February 7, 2013, in Washington.
Honoree and director of pediatric neurosurgery at Johns Hopkins University, Carson poses with actor James Pickens Jr. at the Jackie Robinson Foundation Annual Awards Dinner on March 16, 2009, in New York City.
Before his jump into conservative politics, Carson was known for his work as a neurosurgeon. Carson was awarded the Presidential Medal of Freedom by then-President George W. Bush on June 19, 2008. At that time, he was the director of pediatric surgery at Johns Hopkins Hospital in Baltimore, Maryland.
In a story that garnered international attention, Carson was ready to separate a pair of 10-year-old Indian girls, Saba and Farah Shakeel, who are joined at the head in New Delhi, India. Here, he addresses a press conference at the Indraprashtra Apollo Hospital on October 4, 2005.
Carson and a team of 20 specialists approved the procedure after studying the girls' brains; however, their parents were worried about their daughters' lives and did not give doctors permission to operate. The surgery did not happen.
Carson observes the start of neurosurgery proceedings at the Raffles Hospital in Singapore on July 6, 2003. Carson and Dr. Keith Goh, left, performed a complex operation that was unsuccessful to separate 29-year-old twins Ladan And Laleh Bijani, who were joined at the head.
Trump also jabbed at Carson, applying a line of attack he's used against former Florida Gov. Jeb Bush, whom he frequently calls "low energy."
"He makes Bush look like the Energizer bunny," Trump said on "New Day."
Trump also defended comments he made about Carly Fiorina's appearance in a Rolling Stone profile published Wednesday, insisting he was not talking about her looks when he said "Look at that face!"
"Would anyone vote for that? Can you imagine that, the face of our next president," Trump had said while sitting with a Rolling Stone reporter.
"I'm not talking about looks. I'm talking about persona," Trump insisted on CNN's "New Day."
Trump did not refute the accuracy of the quote.
Fiorina declined the opportunity to punch back Wednesday night on Fox News with Megyn Kelly.
"Well, I think those comments speak for themselves," Fiorina said. "Honestly, Megyn, I'm not going to spend a single cycle wondering what Donald Trump means."
But then, sensing an opportunity, Fiorina added:
"Maybe -- just maybe -- I'm getting under his skin a little bit, because I am climbing in the polls."