"Even though I might be leaving the campaign trail, you know there's a lot of people who love me. They just won't vote for me," Carson told the Conservative Political Action Conference gathering in National Harbor, Maryland. "But it's OK. It's not a problem. I will still continue to be heavily involved in trying to save our nation."
When Carson said he would be "leaving the campaign trail," the crowd gasped, giving him a standing ovation.
Later in the speech, Carson explained, "I did the math. I looked at the delegate counts ... and I realized it simply wasn't going to happen. And if that's the case, then I simply didn't want to interfere with the process."
Carson did not endorse another Republican candidate. He did, however, warn the remaining presidential candidates that a prolonged, vitriolic primary fight risks handing Democrats the White House in November.
"We cannot afford to give the Democrats all of this ammunition," Carson said. "I wish that people would remember what happened last time and how the Republicans were destroying each other."
He used the speech mostly to reiterate his campaign themes, but did also thank his campaign volunteers, especially Braden Joplin, an Iowa staffer who died in a car crash before the state's caucuses.
"It's an experience that I will never forget," Carson said.
Carson defends Trump
While Carson wouldn't endorse any of the candidates, he later told reporters that all of the remaining Republican candidates could do the job of president.
And he defended Donald Trump to his critics -- adding that Mitt Romney's tear-down of Trump on Thursday would "destroy the unity in the party" and help Democrats.
"People who think Donald Trump would be the worst thing that ever happened ... you make a really big mistake by trying to thwart the will of the people," Carson said.
He added that Trump's biggest goal includes being "successful" and predicted a Trump presidency would not reflect all of his campaign rhetoric.
"That's a huge part of him. He would feel terrible if he had a presidency that was not successful," Carson said. "And he's smart enough to know that he cannot have a successful presidency with some of the things that he's talking about, so he would appoint people who were very, very good and very, very smart and he would largely stay out of their way."
Carson to chair Christian group
Earlier Friday, My Faith Votes announced Carson as its new national chairman, putting out a statement ahead of Carson's address to CPAC.
"Nothing is more important to me than my personal faith, and it is my faith that motivated me to be involved in the political process to begin with," Carson said in a statement. "I believe Christians in this country can easily determine the next president of the United States and all other national and local leaders, should they simply show up at the polls."
The tax-exempt nonprofit educational group says it will undertake a national media campaign that will gather steam into the November presidential election.
"In the last four presidential elections, an average of less than five million votes separated the major candidates." My Faith Votes President Sealy Yates, said in a statement. "Yet, more than 25 million Christians didn't bother to even show up at the polls in 2012."
Carson repeated the message
in a video on the group's website, saying it's his goal to encourage all Christians in "exercising our civic duty and voting."
The group said Carson agreed to take on the position the same day he announced he could not see a "path forward" for his presidential campaign on Wednesday. He did not participate in the GOP debate on Thursday.
Asked if the new job would preclude him from endorsing a fellow candidate, Carson confidante and business manager Armstrong Williams said he was "never" going to endorse a candidate.
Speculation had abounded about Carson's next move. CNN's Dana Bash reported
that GOP operatives planned to reach out to Carson to encourage him to run for the Florida Senate seat being vacated by Marco Rubio instead of president.
Carson ruled that out in the news conference after his CPAC speech on Friday.
"It's not something I want to do," Carson said. "Politics and running for political office is never something that I was particularly interested in doing."
The super PAC supporting Carson had also sent out fundraising pleas
off Carson as a vice presidential pick.
Throughout the campaign, Carson has said he'd be happy in retirement but has felt called to run for president by his supporters and God.