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Ms Greene added that she "walked away" from QAnon before she ran for Congress, and acknowledged that "school shootings are absolutely real" and that "9/11 absolutely happened" - US tragedies that she has cast doubt on in the past.
But while she described herself as "a sinner" before God, she also did not directly apologise in her 10-minute speech.
The posture of contrition came as she faced a disciplinary vote in the Democratic-led House after the chamber's top Republican Kevin McCarthy balked at punishing her over her rhetoric.
The furore over Ms Greene has exposed deep party divisions in the wake of Donald Trump's presidency.
Furious at the Republican leadership's lack of accountability for one of their own, Democrats scheduled a Thursday afternoon floor vote to boot Ms Greene from the education and budget committees.
The vote will force Republicans to go on record over Ms Greene's conduct, which includes her harassment of a teen school shooting survivor, trafficking in anti-Semitic and xenophobic tropes, and support of social media posts that endorsed assassinating Democratic lawmakers.
It will be a closely watched moment, as the party attempts the balancing act of accommodating base supporters of the still-influential Mr Trump, and winning back traditional Republicans who have bristled at Ms Greene's unrestrained politics.
'Restore this party'
Republicans huddled in a closed-door session late Wednesday to debate the path forward. Dozens of members reportedly gave Ms Greene a standing ovation when she addressed the group.
"The number one thing that happened in this conference was unity," Mr McCarthy insisted afterwards to reporters.
He notably made the remarks standing alongside conference chair Liz Cheney, the number three House Republican who faced a fierce backlash from conservatives for supporting Mr Trump's impeachment.
But she survived a caucus vote Wednesday to remove her from leadership, in what she called a "resounding acknowledgement that we need to go forward together."
The Cheney vote was done by secret ballot, and congressman Adam Kinzinger said it was "unfortunate" that his fellow Republicans did not "have the courage to defend her" in a recorded vote.
"I think it says there needs to be a wake-up call," he told MSNBC. "It is weird that there's such a low bar right now but all we can do is try to restore this party."
Before running for Congress, Ms Greene "liked" Facebook posts that advocated the execution of Democrats including House Speaker Nancy Pelosi.
In 2018 she asserted that California wildfires were ignited by a space laser controlled by a Jewish family, and she supported QAnon conspiracy theories that a "deep state" cabal operated against Mr Trump when he was president.
"When I started finding misinformation, lies, things that were not true in these QAnon posts, I stopped believing it," Ms Greene told the House.
Ms Pelosi on Thursday curtly rejected the suggestion that voting to remove Ms Greene from committees would set a bad precedent by emboldening Republicans to target Democrats for similar discipline should they win back the majority.
"If any of our (Democrats) threatened the safety of other members we'd be the first ones to take them off of the committees," Ms Pelosi said.