Jimmy Carter delivered a call to help others in his return to teaching Sunday school for the first time since suffering a broken hip last month.
"How many of you think if you do a good thing for just one other person, it would make America a better country?” Carter said to a gathering of hundreds of people from around the country, according to NBC Atlanta affiliate WXIA.
"Is that complicated? No, it's not that difficult."
Carter, who is the oldest living former U.S. president in history at 94, also gave an update on his health and revealed that he had his first conversation with President Donald Trump.
The 39th president had been sidelined from his regular Sunday school duties at Maranatha Baptist Church in Plains, Georgia, since undergoing surgery in May. Carter broke his hip in a fall at his home while preparing to go turkey hunting.
Carter has regularly been teaching Sunday school since leaving the White House in 1981.
He revealed on Sunday that three weeks before he suffered his injury, his wife, Rosalynn, 91, also broke her hip in a fall.
"Rosalynn and I have had some bad luck, lately, with our physical health," Carter said. "We’re getting along fine, now, thank you for your prayers and good wishes."
Carter also said he had a phone conversation with President Trump during his recovery about the economic friction between the U.S. and China. Carter had written Trump a letter about how he had dealt with economic issues between the U.S. and Japan during his term, according to The Associated Press.
"I was delighted, and I was surprised," Carter said. "He was very gracious and expressed his appreciation for my letter. But the main purpose of his call was to say, frankly to me on a private line, that the Chinese were getting way ahead of the United States in many ways."
A crowd of hundreds lined up in pouring rain outside the church starting at 8 a.m. to hear Carter's lesson, which began shortly before 10 a.m., according to the Atlanta Journal-Constitution.
Carter ended the 45-minute talk with a call to serve others.
"Find one person in your neighborhood who might be lonely and make it a point to visit them," he said. "You promise to do that? It will make America a better nation. That is what the Holy Spirit does. It orients your heart and mind toward servant leadership."