– Dr. Helene Gayle was with former President Jimmy Carter in Nigeria several years ago when he met with sex workers to talk about the issues they faced.

The women asked Carter why they couldn’t get enough condoms to protect themselves, and the next morning Carter spoke at the church of the former Nigerian president about the importance of valuing and protecting women, even sex workers, said Gayle, former head of Atlanta-based CARE and now CEO of the McKinsey Social Initiative.

“For me, what has stood out is his vision and his willingness to be courageous and take on issues that others are afraid to take on,” Gayle said.

More than three decades after leaving the Oval Office, Carter is still visible and highly respected around the world. The Carter Center has helped to improve life for people in more than 80 nations, campaigning for everything from eliminating diseases to ensuring free and fair elections and fighting for the rights of girls and women, with Carter often showing up himself.

When he revealed last week that cancer had spread in his body, there was an immediate outpouring of well wishes to the Carter Center and on social media from all over the world — from Elsa, Texas, to South Sudan, where he has monitored elections and worked to eliminate Guinea worm disease.

“Jimmy Carter and the @CarterCenter have done a lot to bridge inequalities of health and build hope. Get well soon sir. #ShareHumanity,” tweeted Patrick Oyulu, a humanitarian worker, from the contested area of Agok in South Sudan.

Carter’s work has taken him to Colombia, the Middle East, and North and South Korea. He has lectured on transparency and reform in China and met with Palestinians in the Middle East. Since 1984, Carter and former First Lady Rosalynn Carter have joined volunteers to build, renovate and repair 3,943 homes in 14 countries through Habitat for Humanity International’s Jimmy & Rosalynn Carter Work Projects.

Carter was asked to be a member of The Elders, a group of independent global leaders, founded in 2007 by Nelson Mandela, that work for peace and human rights.

Joseph Warioba, former prime minister of Tanzania and a former member of the East African Court of Justice, said, “I couldn’t believe he had been president of the United States because he is a very humble man.”

His supporters continue to pray for his healing. Oyulu, who was born in Uganda, lives in New Jersey and is working in South Sudan, said, “People know and appreciate the work he is doing. We want to thank him for what’s he’s done. We wish him the best — all the way from Africa.”