Three days after receiving his first round of radiation cancer treatment, former President Jimmy Carter taught two Sunday school classes, reported CBS News.

On Sunday, Carter led a Sunday school class of about 300 people at Maranatha Baptist Church in his hometown of Plains, Georgia. Carter spoke briefly about his health before quickly moving on to church lessons. “That’s enough of that subject,” said Carter.

Early this month, Carter announced that advanced cancer had spread from his liver to his brain in the form of melanoma. Despite the dire illness, Carter hasn’t let the diagnosis affect his approach to life. “I’m perfectly at ease with whatever comes,” said said. “It is in God’s hands.” Carter’s diagnosis seemed to inspire his Sunday school lesson.

“Say ‘God, I’m really troubled and I ask you to give me the strength to bear whatever I have on my shoulders and to face whatever comes to us,” said Carter.

President Carter has spent the last several years fighting Guinea worm infections in Africa. He recently said that he would like to see the last Guinea worm die before he does.