Biden was the first sitting president to speak at Ebenezer Baptist Church. Sunday would have been King’s 94th birthday.
Atlanta Mayor Andre Dickens and Sen. Jon Ossoff greeted the president on the tarmac at Hartsfield-Jackson Atlanta International Airport.
Biden arrived at the church shortly before 11 a.m. He stood at the pulpit for remarks by about 11:40 a.m.
Warnock introduced Biden, who paid tribute to King and his wife, Coretta Scott King, saying the holiday was "her day as well." Biden called King "one of my only political heroes."
"The world is changing, there's much at stake," Biden said. "The fact is that this is a time of choosing."
Biden called on the congregation to "redeem the soul of America."
"What is the soul of America? The soul is the breath, the life, the essence of who we are," he said.
Former Atlanta Mayor and Biden Administration advisor Keisha Lance Bottoms, who was in the audience, said days before the visit Biden’s speech would "reflect on Dr. King’s life and legacy and ways we can go forward together."
"The president has been very clear that voting, the right to vote, the access to vote is a core component of our democracy," Bottoms said.
Ebenezer will host its traditional Martin Luther King Day commemorative event on Monday, which will be live on FOX 5 at 10 a.m. You can also watch on FOX5Atlanta.com, in the FOX 5 News App, and on social media channels.
Biden last came to Atlanta with Vice President Kamala Harris to push for federal voting reform in a speech at Morehouse College.
Biden avoided battleground states, including Georgia, during the 2022 midterm elections. Warnock was hesitant to outwardly support the sitting president while he campaigned against Republican Challenger Herschel Walker.
Georgia may be a pivotal state for Biden’s 2024 campaign hopes. He won Georgia in 2020 by fewer than 12,000 votes.
On Friday, Bottoms and White House officials described the event as an opportunity for the president to speak to civil rights activists and push for voting rights legislation.
"There’s no better place to do that than at Ebenezer," Bottoms said.
Biden’s visit comes during a federal investigation into the discovery of classified documents discovered at his private residence and an office at a Washington, D.C., think tank. Attorney General Merrick Garland appointed a special council to oversee the investigation.
The Associated Press contributed to this report.