– In theory, it's not the restful weekend one would expect of a 90-year-old who's just started cancer treatment. But Jimmy Carter has never lived his life in theory.

On Thursday, just hours after the extraordinary news conference where he discussed in detail his diagnosis and plans for the future, the former president and governor returned to his beloved hometown of Plains.

His docket was crowded with Saturday night's 88th birthday celebration for his wife, ­Rosalynn, a fundraiser for two nonprofits, and his suddenly not-very-usual Sunday school teaching slot at Maranatha Baptist Church.

Plus, photos outside the church afterward with anyone who wanted them.

His Sunday school lesson was familiar: When your burden grows heavy, ask God for strength.

With easygoing humor, Carter gave back-to-back Bible lessons to unusually large crowds totaling more than 700 people just three days after undergoing radiation treatment.

"Life goes on," said Jan Williams, a close friend and a member of Carter's church.

By publicly combating with grace and grit the melanoma cancer that's been found in his liver and brain, Carter is attempting to prolong his remarkable life while also leading others by example.

And he'll do it, he suggested in understated yet stunning fashion, by agreeing to temper his relentless pace of work and travel.

"I'm going to cut back fairly dramatically on my obligations," Carter told the news conference at the Carter Center, where he also announced that his grandson, Jason, 40, would take over from him as chairman of the board of trustees. "I'm ready to go on to a new adventure."

Since leaving the White House 35 years ago, he has logged millions of miles and traveled to dozens of countries on various peacekeeping, democracy-pushing and disease-fighting missions. Now, the Nobel Peace Prize winner said he intends to follow his doctors' orders and reduce his duties at the Carter Center and Emory University.

He's talked of scaling down his work for more than 10 years — and his wife of 69 years has intermittently begged him to do so — but he said it took getting cancer to finally force his hand. Even so, the pain of that decision clearly lingered, as Carter spoke hopefully about still embarking on a November trip to Nepal to build Habitat for Humanity houses for the needy, even though it could interfere with the end of his treatment regimen.

In between treatments in Atlanta over the next three months, Carter will be spending more time in this southwest Georgia town of about 700 where he's lived most of his life.

Plains has rallied around their ailing native son, showering him with signs of ­support and prayers.

There was no thought given to postponing Rosalynn's public birthday party, organizers say. And, despite being in the midst of an undoubtedly grueling cancer treatment regimen, Carter has given no indication he intends to skip any of his long scheduled Sunday school teaching slots.

In fact, some speculate, just the opposite could happen.

"I think there're going to be a lot more 'Jimmy Sundays,' " said Jill Stuckey, a Maranatha member who helped organize last week's effort to place 500 "Jimmy Carter for Cancer Survivor" yard signs around town. "The dates he'd blacked out (when he wasn't available to teach) were because of trips he was taking for the Carter Center. And he's an evangelist. He sees this as an opportunity to tell the Word to even more people."